What do you mean “ it was worth a try” There is no “try”
There is only DO or DO NOT. (somewhere heard that I did. ..)
Now then, as you said, you inherited a really smelly washer. Thats It!
You also inherited a thick build up in it from too much detergent used by previous owner.
You may have to run three or four of the SuperShock Home Recipe to clean it out. I don't think anything else will work with a thick buildup.
Double the amount of salt and dishwasher detergent. You do not use TechnoFresh with the SuperShock Home Recipe.
Use two full gallons of vinegar soaked into the old towels/rags. I
It is a little expensive but it is the only thing that will actually work to cut through the gunk.
You probably will get black chunks of stuff coming loose. I have also heard of brown, yellow and red “stuff”.
You probably will have the smell get worse before it gets better as you remove layers and expose more smelly stuff.
Keep going until the smell is gone.
This is really common for a really smelly machine.
You are not alone.
By the time you get done you will have also cleaned out the drain lines from the wash machine that are getting plugged now.
The SuperShock Home Recipe will clean the machine and the TechnoFresh will keep it clean.
I have never lost a patient yet.