ok - this may seem like eeeeww, but it actually worked very well. I got a lot of 2nd hand pots - too many to clean individually. I scrubbed one with a brush to get rid of loose grime and then stuck it in the dishwasher, top shelf, on an anti-bacterial setting........and it came out almost as good as new !
Now for the rest !
BTW - these are sturdy plastic. Haven't tried any other type.