Not on this site i havnt, but done it on another while in a live chatroom on another site, with a lady friend on the other end.
We had discussed my need to do this, and i told her i was off to insert a suppository and put on a disposable nappy/diaper, then came back to chat more.
As time went on, she would rmind me how long id held it, so we were both aware of the outcome, it was three quarters of an hour later when i just couldnt hold any longer and my ass exploded , filling it !
I got up and could feel more coming out, i was pretty empty after a few minutes.
She shared all this info, and is wanting to meet to do all this to each other, so cant wait.
Then off to clean up, tipping the majority down the loo, putting the soiled nappy in a bin bag, then having a good shower, takes a while to clear up after, but is worth the trouble every so often.