I think that even if you call them, you would get the same answer you have gotten here. You have to be able to show your room card in order to get a wristband to swim at SAB. There have been reports that people have been told be a CM that they could have guests, but I really think those times are few and far between. This is an incredibly popular pool.....the folks that are paying to stay at either YC, BC or BCV like to be able to find a chaise and have a nice experience. I know how bad pool hopping is at the Polynesian and it isn't nearly as nice as SAB.
Now, I'm one of the few people that isn't all that crazy about SAB....we did it once and that was enough. If you want to spend time at a pool with your friends, I would go to a water park or even to their resort. I wouldn't want to have either you or your friends be embarrassed by a CM at SAB. I have seen them ask people to leave, so it could happen.