I can see the benefits if you dont want a litter tray in the house.. and if you know when your cats go for their poo's (my Alfie & Lola are like clockwork) then you can just go in and flush it.

However, dont know if it's cruel.. a cat wouldnt do it if they didnt want to.

But think I'll keep their litter tray for now.. dont fancy sharing a toilet with the kits! lol