I saw Eddie Floyd perform it with Solomon Burke. That was really really great (and weird - Solomon's son introduced Eddie Floyd and the Viennese audience just didn't react - we had no idea who he was...)
Knock On Wood is a rather mediocre song. I never cared for it, no matter which version it is. Plus what does this have to do with the Rolling Stones? At least show it as off topic, please.
Sumfin like that, yeah.. Never - besides - either forget the personal meeting with Bill I had plus the long phone-interview from which I extracted some minutes to Tell Me once.
Eddie Floyd has that Otis-groove noone else has today.