I took beta blockers for some months for medical reasons unrelated to performance. I no longer take them.
They did, for me, reduce some of the physiological symptoms of stage fright, particularly the sweaty palms and dry mouth. However, they also adversely affected my playing, and led to cold hands (less circulation) and exacerbated some problems with joint pain.
I no longer experience much stage fright, typically, though if I make a series of mistakes this can become a cascading problem. That is troublesome in those situations when I am asked to sightread in public (the "oh no, we're singing this hymn" situation that is the bane of all church musicians) or get flustered by missing a cue or jumping a cue or playing the wrong number of verses.
For me the beta blockers weren't worth it and I certainly wouldn't seek them out for performance reasons alone.
As Shasta points out the beta blockers will not affect your thinking, just your body's response, so at best they only address part of the problem.
The best solution, IMO, is to skip the beta blockers and just play out a lot. Play in front of everybody, in informal situations, alone, with others, and make your music no big deal. That works for me. But then, I've never had a high-stakes audition, because I don't try to bat in the league that requires them.
If you decide to pursue them, work with a doc who can make sure you're using them safely, and be sure you know how the drugs will affect you before you use them in a situation where the outcome is really important.