Hello, I’ve recently acquired 20-40 of each denomination of the 1961/1991 USSR ruble notes. I was wondering if anyone knew if these would be safe to lightly clean/wash with water for safe handling in an immersive USSR-themed board game.
I understand this is a topic of controversy in the money collecting hobby but these notes are all thoroughly circulated and after much research on each note, I have not found any sort of rare variant among them.

