In summer mine are in a 4 ft square rabbit run, with the top covered when it's wet, and every two or three days I just move it on to clean grass by sprinkling a few mealworms along the side of the run that I'm pulling towards me. Then they all run to that side and I can pull the cage along without removing them. Then I rake up the droppings from the grass, or leave the rain to wat them in if it's very wet. The area I've had them on this summer now has excellent green grass from the fertiliser. I have to open the top of this run to see to their needs but only once this summer did one of them fly out, and she looked very surprised and was easy to catch. If you always move quietly and slowly they soon get used to you.
When it started getting damp and cold in the autumn, I moved them to their indoor cages. These are 2 ft by 3 ft, and 15 ins high, built in to the back side of a sort of summerhouse come shed, with glass doors and windows at the front to let in as much light as possible. I keep a spare cage, all set up and clean, with feeder, shelter box, dustbath and drinker all ready, then when I want to clean out the old cage, about every 10 days, I just put my hand in and pick them up one by one and swap them into the clean cage. They are used to my hand coming in to the cage to feed them their lettuce and mealworms, top up the dustbath etc, so they don't get alarmed. I just keep the shed door shut whilst doing this as sometimes one of them sort of falls out of the cage from over- eagerness to get whatever is on offer, but she just drops to the floor, looks surprised, and I pick her up and put her back. Having a spare cage set up is useful also in case one of them is attacked or ill, so you can just pop her in there whilst working out what to do next. But at first, before I had this, I just got a cardboard box, used an old freezer shelf as a lid, and popped them in there one by one when moving them around, and the replaced them when the cage was ready. You soon ge the knack of putting your hand over the quail and holding her from above with one hand. It's not like a chicken as they're such small birds.
At the moment I'm using Smartbedz straw pellets on the cag floor, which are effective at controlling odour as they are very absorbent. One drawback about quails, sweet as they are, is that they do have problems with personal hygiene, shall we say. Put more crudely, if not kept clean they soon stink. Their poos are small and sticky little blobs, which you can't pick up like you do with chickens, because of their high protein diet. So you need a deodorising litter for the base. The Smartbedz pellets are very effective, better than wood shavings, but when I've finished up the bags I've got I shall try the Aubiose I'm now using for the hens, as it's softer and I think will be nicer for their little feet to walk on. If inot kept clean and dry, quails get poo balls on their claws, which can develop into nasty big lumps and it's a pain trying to soak these off. I do find their feet stay clean on the straw pellets though.
When the birds are happy in the clean cage, (or safely moved to a temporary box) I just get a dustpan and brush and scoop out most of the dirty litter and dump it in a bucket. Then I just slide out the vinyl cage liner, bending it as I go to retain any leftover bits of litter and swoosh them into the bin, spread it out on the ground and wash, disinfect with a spray of Poultry Shield, and dry it with an old towel before sweeping out the remaining dust inside the cage and wiping round. Then it's easy just to reassemble everything and I've got the next spare cage ready for when it's needed. Takes about ten minutes. You could do this without the liner, but if you have one, it's easier to wash it without making the cage wet, and also saves reaching in to the back of the cage which can be a bit hard on the back.
I know some people keep their quails successfully all year round on a fixed earth floor in a more aviary- type situation, and I shall be interested to hear from them about how they manage to keep the ground clean in winter. Yes you could keep them in an Eglu, but if you're talking about the smallEglu Classic sort of thing, there might be problems moving it on to clean grass as they're quite heavy, I found, and with my Eglu it was a pain not being able to get into the run easily. Quails don't roost like chickens, mine do seem to like one or two little shelters in their run or cage and sometimes they lay in there, but often it's just all over the floor and they don't go to bed at dusk, they seem to be more nocturnal than chickens and often just camp out anywhere, so you wouldn't be able to train them to go into the Eglu at night like chickens. They don't need very much space either - commercially farmed quails have a recommended floor area of 9 sq. inches minimum (!) but mine are very happy at 3-4 girls in a 6 sq. ft cage. So the space inside an Eglu would perhaps be overkill unless you had lots of birds!
If you are thinking of starting with quails, the best time might be in Spring, as they stop laying in winter unless you can provide 14 hours of supplementary light. I did get the 'quail bug' last Autumn, and learned a lot from my first batch over the winter. Ihowever, ie just how to handle them and what their needs were, then I hatched a couple of batches myself in February and these are the birds that have been laying so well all summer and are still laying an egg every day (because there is light on a timer in their indoor cages.) I found it a very steep learning curve after becoming comfortable with chickens - they are quite different in many ways, and it does take time to find out what works with them. The chicks are delightful, and if I could manage it successfully at my first attempt at hatching, it must be pretty easy! And of course they do start to lay at around 8 weeks, not 20-30 weeks like pullets. But there can be awful problems with aggression from the males - I had several girls ripped to pieces by young sexy males and in the end I culled all the males I had hatched and have just kept the girls, who are peaceful and productive on their own.
