old post on the subject with much info:

https://board.moparts.org/ubbthreads/show...rue#Post2774863

My experience with Techron
and with the 'honey colored' Gumout with 'Regane' in the small print has been good

I did an experiment once where I soaked eight 1994 Magnum 5.9V8 pistons in coffee cans filled with various cleaners including Techron and Regane, but found that the German brand prefered by Mercedes, VW, BMW and Porsche called
Lubro Moly "Ventril Sauber" (in English 'valve cleaner') and
"Jectron"

http://web.archive.org/web/20051207222426/http://www.benzstuff.com/lubro-moly.htm

dissolved more carbon deposits from the crown of the piston, for whatever that is worth.

I do not maintain that my test with the eight piston crown deposits duplicates what you need to happen when you pour any cleaner in your fuel tank.