I too use Carefresh. Our rabbit specialist vet said if the buns eat a little it won't harm them (I find that hard to believe). Yes it is messy but the hay really works. I've also bought the cat pans that have a plastic basket-like grid that sits on top of the litter and they have had no problem using it, plus it keeps their feet cleaner and dry when they linger in their litter. I've put hay in the basket part of that one too. For some reason they like to sit, eat and pee at the same time so it works out well. Yes, pine/cedar shavings are bad-bad-bad for their respiratory system. Hope this helps.