Cottontail can not be trained to be a pet.
They are simply wild and different from domestic pet rabbit.
Having a pet is the same be it you have a dog, a cat or a rabbit.
Domestic rabbit can live up to 12 yrs while cottontail usually live around 3-4 yrs.
Pet rabbit can be train to use litter box and they are smart.
However, all kind of pet needs commitment, not just a spur of the moment kind of thing.
Domestic rabbit need interaction with their owner and not just put in a cage all day.
I work as a volunteer at local rabbit rescue and if any of you are interested in rabbit, please consider adopting one instead of buying from a pet store.
Any other question about rabbit as a pet, feel free to pm me or post it here.