enblethen wrote:
Thetford toilets have a double seal gasket where the blade slides in.
Thetford made/makes a tool to clean it.
I made one out of a metal coat hanger. I bent one end with about a one inch point. The length is about 6-8 inches. Insert short into groove to remove any debris.
I made the same type of tool and clean it out occasionally. My seal is 25 years old and still holds water. If it runs dry for any length of time it will leak, it won't leak as long as water is in the bowl and seal is clean.