I got lazy after brewing my last batch and left the grains in my mash tun (10 gallon Igloo cooler) for about a week before tossing them and cleaning it. It still has a bit of a funky smell. The best I can describe it is sort of vegetal and like the grains had started to decompose. I don’t detect any sort of sour smell.
Any advice for cleaning? I've got some Oxyclean and tons of StarSan. I was planning to brew this coming weekend and don't want to ruin future batches.