Whatever container you use, it needs to be at least 40 cms deep and deeper is better. This is so they can get in it, roll around, scratch dust over their feathers, then stand up and shake their feathers to get the dust out. It’s not called a bath for nothing! You will need a good 15cms of sand or earth in the bottom, plus 25+ cms for the sides above the sand. If you use a shallower litter tray it may tip over when they stand on the edge, and in any case if it’s not deep enough a lot of the dust will be lost over the edges when they scratch and shake, and you will be always refilling it. I have the upturned base from a large plastic water butt, but any large deep box will do. Plastic is OK if deep enough as the weight if the sand or earth will stabilise it. It’s nice for them if the edge is thick enough to perch on, but if it isn’t you can fix a perch made from wood across the edge for them to hop up on to. I don’t think a litter tray is deep enough to do the job. Or you could perhaps make something like a deep sandpit with wooden sides, and then you could make it big enough for a communal bath, which they will love.