Here are ALL the things I tried, many of which worked temporarily, and what finally worked permanently:
1. cleaning the filters (back then I had to use ammonia and Dawn; rinsing didn't work)
2. dishwasher cleaning product
3. vinegar in bottom of DW before starting
4. adding bracket to secure high loop to back wall under sink
5. hiring someone to reinstall the DW (who found that the original plumber hadn't followed the installation instructions; he hadn't used the loop bracket on the side of the DW at all)
6. totally replacing the drain hose twice, which was filled with rotting gunk (worked for 6 months)
7. turning our Rinnai up to 140 degrees F. and being sure I ran the faucet til the water was hot, before starting DW.
8. citrus cleaner soaking in filter cup overnight before running dishwasher
9. cleaning disposal with a special cleaner regularly
10. wiping dishes clean of all debris before loading
11. buying the old type of DW detergent WITH phosphates on the internet (called Boil-Out - it's Cascade's original formula) - this did help a lot in getting the dishes clean and getting rid of a jellyfish-like debris in the area where it lets out steam
and 12 - FINALLY, after 7 years of the smell returning, we FINALLY learned that the original Rinnai tankless water we had, and the new energy saving dishwashers are not a good team. The DW's call for hot water, since it uses less, is satisfied before the Rinnai has a chance to heat up enough water hot enough for the detergent to do its job. So even though my initial pre-rinse water was hot, by the time the DW got to the wash cycle, the water in the pipes had cooled, and the wash cycle was only getting warm water. The heater in the DW was not effective in heating up the water quickly enough, and sometimes the cycle would go for 3.5 hours. Sometimes I'd turn it on before I went to bed, and the dishes were still hot in the morning, meaning it had run most of the night. Also, the original plumbers made too long a water-line run from the Rinnai to the DW, AND had used too small a diameter gas pipe. In the winters in upstate New York, when our gas furnace, gas fireplace, and gas dryer were all on at the same time, and water is entering the house just above freezing, the Rinnai wasn't getting enough gas to heat the water up fast enough nor to a high enough temperature. Therefore during the rinse, there were globules of debris and grease settling out of the water into the lower folds of the corrugated DW drain pipe and sitting there to rot. The new tankless heaters solve the problem of too much cold water in the water supply line by having their own recirculation pump and a small one gallon reserve tank that always stays hot. We bit the bullet and replaced our Rinnai with a Navien (not as much as starting from scratch, because everything they needed was there except the wider diameter 10 feet of gas line) and now everything is working GREAT! And we no longer have to waste gallons of water on the second floor waiting to get hot water for taking a shower or washing our hands.
Each of the previous solutions we tried helped a little bit, so we kept thinking we'd figured it out (I had had several professional plumbers and dishwasher repairmen here over the years) but it wasn't until I hired a man with 45 years experience that we together, doing research on the internet, figured it out. Apparently they are having this problem all over the country.
Good luck to you all in your own stinky-smell-solution-search. Your problem may be different from mine, but I'm glad we kept trying until we got to the bottom of it.
Sincerely,
Barbara in Rochester, NY