This is one of those things that it's better to not know.![]()
I'm not a bar, but I clean my lines only when I change the keg. I use PBW which is kinda like oxyclean, then I flush with water, then I flush with starsan (a acid, food safe, sterilizer). I clean my taps the day after they get any use and I keep plugs in them when not in use. I use high end taps so they are forward sealing to prevent a lot of the problems that come with cheap taps (sticking, gumming up, etc).
I was a bartender for 5 years in a college bar. I never cleaned them or witnessed anybody clean the taps. The Budweiser guy may have but never in my presence. He would get pissed when he would catch us serving Milwaukees Best and Best Light out of the Bud and Bud Light Taps. Good times.