I've given them a brief rub with a pencil rubber which cleaned them a bit, I haven't cleaned a lot of my coins which aren't of my main interest as I might eventually sell or swap & leave the cleaning to the new owner
You've been showing some really delightful pieces--really--and I've experienced the usual collector's mix of admiration and envy. (The Thai copper was...wow!).
But I have to confess that when the top of this coin came into view, what went through my mind was something like "Dang, chrome; someone's ruined this thing...well maybe not ruined. But not helped."
The subject of coin cleaning is a minefield I know, and I myself routinely remove glue and tape residue with acetone, and wipe or flick dirt and wax off the surface of coins--but ever since I took a pencil eraser to that '51 Franklin as a kid, I've known I'd never do it again.
But of course we all have our own opinions of what makes (or unmakes) a coin's eye appeal.

v.