Okay one more final update. I got in touch with support at Five Star (prompt and helpful.) They recommend B.S. Remover (best product name ever?) at 1 oz./gal. for quarterly acid cleaning.
I just went through the 5star site looking for something akin to B.S. cleaner, I could not find it. Are you being sarcastic or did I miss it? :o
Thanks
FWIW, I recirculate BLC for a couple hours with all my 3 taps and lines interconnected every few months
Beer stone remover. I’ve never seen it in shops, but I’m sure it can be ordered.
Not kidding, it’s called B.S. Remover and though it’s been around awhile their site may still show it as a coming attraction. They have it at my LHBS (shout out to John & the family): http://www.grapeandgranary.com/homebrewing/sanitizers-and-cleansers/beer-stone-remover-8-oz.html
There are several brands out there: Robot or human?
There are various brands, in fact the maker of BLC caustic makes an acid cleaner called ALC. LHBS carries BLC but not ALC, so I checked on the suitability of B.S. Remover for line cleaning. (It’s not labelled for this use.) So you could probably find any number of combinations of products to do the job. It was useful to get tech support from 5Star on that. Apparently all you need is to make sure, if you do regular caustic cleaning to remove organic material, that you periodically run an acid capable of de-stoning. DBQM (see my post above) outlines the goals, we just need to find solutions that match our resources!