Information requested on breast forms

Hello ladies, I'm a 'newbie' on this site and have read some great stories. I've had some writing experience but not in this genre, so I am trying my hand at it. My chief character buys some adhesive breast forms like those advertised on the home page. I understand they have to be removed on a regular basis. Can anyone tell me how often and how long they have to be kept off? Also can they be worn while having a bath or shower or will that loosen them?
Thanks for your help, Theresa