Is It Safe To Soak LWC In Acetone?

It shouldn't, no.

For "dirt", literal physical grow-crops-in-it dirt, just plain water is OK (distilled/deionized rather than tap water because chemicals in tap water can cause bronze disease under the wrong conditions).

I have heard of people getting strange reactions from soaking bright copper coins in acetone. But what I suspect they are really seeing is the acetone removing the gunk that was obscuring whatever it was they were seeing. That, or the acetone they were using wasn't very pure.

They were also soaking the ocins in acetone for, like, weeks. Acetone doesn't need weeks. If it doesn't come off after a few minutes, a few hours at most, it isn't going to come off in acetone.

Thanks folks..

I just pulled some 1943 steel pennies out of 100% acetone, they were so black you really couldn't tell they were steel by looking at them. Now they are much nicer.
Wish I had taken a "before" pic. I will scan and post them tomorrow.

Now, to refill the jar and dump the LWC's in them.