They won't let you. However there may be some sort of special permission to get exceptions for medical conditions that I am unaware of. Regardless you do get breaks. Can you go two hours without applying the cream?
I don't think it'll come off from the time you put it on during breaks... it's a cream, so it should stay on during that time. You can't take the bottle into the center with you... You bring up a good pt tho, which makes me wonder... You think they'll let me take breath right strips into the testing center??????