I, on the other hand, managed to dissolve two of mine today.
Ok, they were both unknown quantities that had been rescued from a junk pile years ago and left to gather dust at home. Today I remembered them and took them to work to see if they’d be any use. A quick blast from the compressed air line removed much of the dust, so leaving them in their mounts for easy handling I gave them a rinse under the tap.
Only to see one lens start to dissolve and melt away – I’m now guessing it was actually a rather expensive salt plate. Bugger!
The other lens washed off fine, so still pissed-off about the first lens – and thus not really thinking – I gave the second lens a clean with tissue paper and acetone. It promptly frosted over and became tacky – a bloody plastic lens.
Two items that had sat on my shelf for near on ten years destroyed in a few minutes. The only saving grace was that both lenses were too scratched and damaged to have been much use anyway; the plastic one especially – it would strongly absorbs the light from my laser diode. The mounts are at least still useful.