I'm sure that bleach or initially soap, hot water, and agitation would take care of most of it. Perhaps bleach afterwards to sanitize. It wasn't dirty nor was the smell or taste terribly bad, just enough so you started thinking about zorba the greek! I rinsed it out really well and, as I said, use it to water cattle. I doubt you could smell it now that it has been filled and drained a dozen times. I am going to get a couple more and will clean them well before storage of emergency water. Note that I always chained it into my tractors front end loader bucket before filling it. Once full, you are not going to be moving it very much by hand. The one I got was very heavyduty, round, strong and water tight if you use the rubber gasket under the screw down lid.

Jon