The litter is more for inside the cage than outside.
Some people use litter (bedding) in a litter pan inside the cage because they use fleece liners. So if you mean house train them inside their cage, then yes people have. For some it works but some it don't.
yeah. outside..uhhh probably not. inside.... most likely. My chinchilla has 2 spots he pees on and when i put in his litter he pees everywhere but in it. so i guess it doesn't really work for me although i pad the pee zones with more news paper just in case.
I have 6 chins, "Litter Pan" in all 4 cages - ONLY my Male/Female pair use their litter box ! My boys use theirs as a "Snuggle box", The other male and female use theirs to store their toys ! However, With my pair that DO use their litter box, sure cuts down on cleaning their cage ! Wish I could get the others to do the same ! Smiles, Oh well ...
(I have used pine and aspen with same results).
Critter litter is gross! When it gets wet, it turns into clay and sticks to chin feet. Just use a pan and put regular wood shavings or recycled litter in it and then put it in the corner your chin urinates in.