It was Ken Waller who played "the King", in "King of the Beach". There were several other California based body builders in that episode, as well as a bunch amatures. Even Lou's stunt double, Manny Perry, also a body builder, got a small speaking role. I believe that Lou may have had something to do with getting some of his fellow "gym rats" included in that ep!

From what I've read, Bix was Lou's acting mentor and I'd rather think that playing opposite Bix would have been more exciting and instructive for Lou than nerve racking. Bix was right there to help Lou out with any problems or to give advice whenever needed. I also have a picture of Lou where he appears to be directing the action during the gym scene. If Bix was Lou's mentor in all things acting, then Lou would have certainly been the on set "go to man" for all things bodybuilding!