I tried it once and learned my lesson. My dd was the youngest and was the only kid who was potty trained. His 5 and 6 year olds were just piss/shitting themselves all over my apartment. They broke all of my dd's things and pretty much did nothing but whine this ear piercing cry 24/7. I ended up having to be medicated for depression, they literally made me want to off myself.
I came to realize that I hate kids who aren't my own and it's not fair to anyone if I try and fake that. I dumped him and was just so incredibly happy.