Use toilet in winter with no or little water, chemicals only

[Murf2u]

It does evapourate in the WW tank, that's why they put a snug-fitting lid on the reservoir with only a tiny hole to act as a vacuum-breaker.

On top of that very few WW reservoirs are 2' x 3' or bigger, that's a LOT of surface area, and with a roof vent designed to create a vacuum on the tank with air moving across it.

[cwit]

Every fall I buy 5 gals of the pink stuff ?This year 15.00 dollars. Winterized camper with it and then use air to blow it back out 1&1/2 gals. That and the rest goes into black tank. For our trip to Florida. In January. We bring a 2 gal jug of water to flush toilet. Worth it to us to be able to use toilet with no problems.

[airstream190]

Can you mix Blue and Pink (washer fluid and RV antifreeze)? Maybe put 1 gal of pink that will not evaporate and then flush with blue?