I'm not sure what you mean by caught. There's no reason I wouldn't use the garbage cans at the rental to dispose of diapers. If the host seeing used diapers in the trash counts as "caught" then I'm sure many people have been.
I have heard of AirBNB not renting to potential customers due to other issues such as sexuality or age but not specifically for diaper use. IMHO after you have rented and disposed of your diapers, whats done is done. It's the renters problem now if they want to be offended by a diaper in the trash can.
And it would be a legal problem for them if they didn't rent to you because of your disability under the Americans with Disabilities Act (assuming its in America). There are similar laws in most other countries though as well.