I’m sure they would look much better if cleaned like when they were new...............
But the patina adds to the look?
Pressure washing is often a bad idea.
Injecting water where a raindrop doesn’t go, waiting for a few freeze cycles, to open the minuscule crack and let the rain in.
Then frost wedging can make fast work of it.
Well, quicker, anyway.
Giant 55 gallon drums of Tilex, should take care of it............