Speaking of really dirty 22lr ammo...
AKC mentioned a couple, so I will share a tale of my worst one.
Back long ago, perhaps in the late 80s, a friend and I bought one or two cases of 22lr ammo made by Norinco. Or at least it had their name on the old style yellow cardboard box of fifty. It was a cipher; SV, 40gr bullet; and it would not cycle most autoloaders. Perhaps they skimped a bit on the powder charge - it was slower than most SV - but we jokingly decided it was because they cut the powder with sawdust. It smoked and stank and sparked with every round, but there was no issue with the smoke obscuring the target since the slightest breeze would waft it away before you could clear the jam. We both thought they smelled like lightered wood (fat pine), which may be true since lightered stumps were once collected to make gunpowder. Perhaps they still are. If so, this propellant needed more process time. LOL!
We eventually shot most of it up. One day I found some remnant boxes and tried them suppressed... they were still filthy, stinky and smokey, but they turned in reasonable groups and were quiet due to the somewhat slower than normal MV. Used in a bolt gun, the cycling issue was obviously not a problem.
So they weren't entirely useless after all.