KMC: Welcome to the site. You are never suppost to caulk around the base of the toilet. It does sound like you have a wax ring problem. He would only use two rings if he saw a problem that he thought the extra ring would fix. It likely didn't do the job, so the question is, what was the problem he saw and what else can be done. Often people install new tile floor with backerboard or something and don't raise the toilet flange.