sogy diapers

I have heard of people useing differencce stuff to simulate a messy diaper. I know some of like to mess and some dont, I have tryed it befor I dont mind it but I dont do it offten to much clean up and hard to hide with people around. has anyone used other things to simulate a messy diaper befor? what have you used? good idea or bad idea? I have heard of people sticking bananas in their bottom so its realy like messing but not. IDK that seems like it would still be just as messy as just going. how do you stop the real thing from comming out at the same time? interested to hear peoples storys if they wana tell them. I myself have tryed oatmeal befor and it works but your diaper tends to soak all the water out of it or most of it but it does work well.