How to clean the crust off this tag?

Use salt and vinegar, let it soak for about 10 minutes, it should clean it right up

NOTE: Although I've never had it happen, it "could" damage the tag (Although I doubt it)

I use salt and vinegar to tumble all of my clad and have never had an issue, so I doubt you'll have any problems.

It's a neat find

tag

I use straight vinegar--- soak it--sometimes overnight-works great... Tony az

The method I use::
First, wash the item as best you can with mild soap and water. Dry.
Heat up a little hydrogen pyroxide in a plastic cup -- enough to fully cover the item -- heat in microwave for about 15 seconds.
Drop item in cup. It will fizz for a while - maybe an hour. You can remove the item and reheat the peroxide if you wish.
When finished, rinse item thoroughly (you might want to coat it with a paste made from baking soda and water for a few moments, to be sure the peroxide is nuetralized).
Coat/protect with a very small amount of petroleum jelly.

Ok thanks for the input guys.

First Ill try soaking in vinegar for a day. Does it have to be white vinegar or will apple cider vinegar work?

After that Ill try the hydrogen peroxide.