Anyone remember the mixture for the black tank? I thought it is 1 cup Stay so Soft and 1 cup of Dawn dish washing liquid. My wife said I’m missing an ingredient. Who’s right?

1 cup of Dawn dishwashing liquid and 1 cup of Calgon water softener is generally known as the GEO method. Borax can be substituted for the Calgon if necessary.

I think a good squirt of Dawn is more than enough, if some el cheapo stuff maybe a cup, but a cup of Dawn would take a month to ever quit sudsing up.

The Tank Cleaner Guy said to use some el-cheapo Mr. Clean or Pine Sol and throw in a little Calgon if you like. His reasoning, is that most of the time things don't sit in the Black Tank long enough for any of the chemicals to break down the solids.
I've been using some Dollar Store Pine cleaner and Calgon and everything seems to be fine. My black tank idiot lites are actually working.

We tried the pine cleaners for a while & I found the pine scented s##t smelled worse than the straight s##t when dumping. Now with the water softener connected every time I just add el cheapo dish/laundry soap from the dollar store, works as good as any.

I guess it's a case of whatever works is fine. Main point being that there is no need to buy expensive products to flush down the sewer because they don't stay there long enough to do anything since these are just "Holding Tanks" not septic tanks.