Interesting question. A couple or few years ago our male cat peed on the top of my big Midway USA range bag. Water, soap, soaking, rinsing, repeating...and waiting a little while...did the trick. I still consider replacing that bag but, well, it still works and I don't notice the smell anymore I don't think so
For ammo I would take it out of anything it may be in and rinse it off with water, then air dry or dry in front of a fan. Should be fine, though I wouldn't let it be used for anything other than range practice and maybe if I wanted to be extra careful, for slow fire type practice just in case it found a way to squib