I can’t see anyway to eliminate aptasia or any hitchhikers for that matter... its part of having a reef tank. As you add LR and LS you will bring things into the tank that you don't plan on. It's usually good stuff, but not always. Berghia, vinegar, joe’s juice, etc. can handle the aptasia, but don’t totally eliminate them... EVER! You can trap many hitchhikers like undesirable crabs, worms, etc. but remember that many of the things you’ve been told aren’t good really are, like bristleworms. My advice is to be as careful as possible about adding LR and deal with the problems they may or may not come up. Since you already know there will be some aptasia, then you will need to deal with them with one of the many methods that are available.

Washing the LR in vinegar probably is a really bad idea… I’m not sure about the affect it would have, but I doubt it would kill the aptasia if it’s not directly injected into the body.

Drying the LR before putting it in the tank would certainly kill the aptasia but it would also kill everything else

Trying to QT LR seems like a waste of time to me… I really don’t know how you would get the “bad stuff” out of the LR no matter how long you QT’d it. Maybe there’s a way that I don’t know about, that’s totally possible!!!

If it were me, I think I’d add your good LR and 6 or 9 berghia… any aptasia that gets big enough I’d inject with plain old white vinegar (that’s the only thing I’ve had any real luck with).