Good point. I guess @adreamy being Korean moderator might ask there (or already did).
I’ve also done overpass query to show amenity=* tags (ignoring common ones which certainly won’t have anything to do with this like amenity=restaurant etc) - so it can be used by @adreamy to run it at places which they know is likely to have such places to clean foot/clothes. (of course, it would only work if they were mapped as amenity=* tag and not something else).
It has found some amenity=compressed_air at suspicious locations, like Node: 에어 컴프레셔 (8134118602) | OpenStreetMap, but if one knows where to look for, maybe other could be found too.