Acetone Use

I put them in a glass small canning jar. I don't really think it makes a difference how long. I usually do overnight. I use a polyethylene tongs to get them out and in. I have another jar that has distilled water in it. I take them out of the first jar, swirl it around in the second jar, and then swirl it around in a 3rd jar that has clean acetone in it. I then let it air dry. I don't think it matters what metal you use because the acetone will only affect organic compounds. And, of course, metal is inorganic. Use ventilation and jars that can be sealed. Make sure the seal won't react terribly with the acetone. On the canning jar, I took the rubber gasket out so it is only a metal to glass seal. Not good for long term storsge but works OK for this purpose.

I've had no issues using acetone on copper. I do agree that it's wise to avoid sunlight when soaking--just find a place far from direct sunlight. Small glass jars with lids work great. I usually soak overnight was well. Longest was two weeks--took that long to remove all traces of very old gum-like crud from a time long past. Good, thorough rinse to follow.