I had a similar problem, I had the "cracker" in my new to me TT. I bought a bottle of digester, poured it in, and filled the tank all the way. Let it sit overnight then took it to dump site. Completely filled and emptied the tank multiple times, using a 5 gallon bucket as a measure of how much water I put in. After multiple rinses I had gained 5 gallons of capacity, and more importantly I was able to get rid of the horrible smell in the bathroom.
I now use lots of water, and use the black tank rinser whenever I can. I am certainly a believer in the digester, it worked for me.
