I clean mine out everyday and do a cage scrub once a week, I use shavings ( a small amount) on newspaper but they have a snuggle bed.
I have gone back to fleece today and yet again one of the boys have tipped the tray up which has sawdust layer and a load of readigrass in mallethead
Apart from duck taping the thing down I'm not sure what else to try lol, I did use a Pyrex oblong china dish, which only had hay in it and they dived head 1st in to scoop it all out and then sat in the dish and eat the hay that was everywhere, this time I have hay in the rack and the tray under it with the shavings and grass in, needless to say I have taken the tray out, at least this time it stayed in the cage for 15 mins which beat the 5 mins the last one lasted lol
So we will see, I'll probably end up back to the paper and shavings etc