Ron:
Don't know if this product is any good or not but advertises as also cleaning sensors:
http://cgi.ebay.com/ebaymotors/ws/eB...7304&viewitem=
Also, see this article:
http://www.rverscorner.com/Holding_Tank.html
I may try this, or something like it, next season. If it works, great. If not, back to the head scratching.
-- Edited by dwhatty on Wednesday 18th of November 2009 09:47:12 AM