I sometimes let my chins out in the bathroom. Mostly, I let them out in the little room where their cage is. I've covered the lower walls with cardboard boxes, so that they don't chew the baseboards.
A couple of month ago, I bought one of those giant plastic balls for my chins, so that they could run around my apartment without eating everything, but only Maureen with get in it and run around. So I have taken them on more trips to the bathroom, and they seem to like it.
Just remember to cover the toilet. Chins can't swim.