Bill,
I agree the water softener and detergent combination is something I will try.
I have heard many times that "bleach is bad" for the Thetford seals, and I found
this link at their European web site but I can find no other reference on the web that bleach damages rubber. Can you or somebody point me to some factual information on that point?
Bleach is one of the most available disinfectants we have and I just checked the Clorox bottle says "wear gloves". One must assume they mean "rubber gloves"...
So, if I use calgon and detergent when camping and then when I get home I clean the Thetford by adding a little bleach to a fully charged unit, flushing several times, then draining and rinsing again with plain water does anybody really think that would really hurt the seals?