The directions for the toilet on a 2012 Interstate with a macerator do not mention which chemicals, household or ready made, are to be used in the toilet if only being used for urination.
There is a huge array of choices.
The best is the Thetford Campa-Chem, but it is formaldehyde based and cannot be used in CA and other states.
Also should not use formaldehyde based products if you are on a septic tank.
Other, more "green" choices range from less effective to ineffective.
Not sure if the 2012 Interstate has separate black water and gray water holding tanks.
If separate, always put a gallon of water back in the black tank with 4 ounces of Campa-Chem after a dumping and after you close the dump valve.
Always have water in the toilet bowl to keep tank smells from wafting into the coach.
No need for chemicals in the gray tank.
Hope this helps.
__________________ Ken L
2019 Flying Cloud 27FB
2020 GMC Sierra 1500 Crew Cab 6.2L Max Tow
We have used 5 Star Happy Camper for several years and been very happy with it. Originally picked it up at an RV show and now reorder from their website.
2012 Interstate Coach
From All Over
, More Than Anywhere Else
Join Date: Dec 2011
Posts: 10,868
In my Interstate, I use SeaLand Clean'n'Green bowl cleaner and tank deodorant, which is formaldehyde-free. I bought my first bag of 12 two-ounce packets at my local West Marine, but it's also available at Amazon, Sears, Gander Mountain, and other retailers.
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