Be positive it doesn't have any tacks, pins, etc (metal) inside it, or your thrifty buy might include a new microwave!

I wouldn't put anything unknown into the microwave. They usually do some sort of sanitizing at the GW so I'm pretty sure any of the suggestions above will help you make sure. The dryer seems the best bet.

If it looks like it's in perfect condition I wouldn't worry about it, actually even if it wasn't in perfect condition, I wouldn't worry about it, you will after all, be washing the clothes that you will use it for.

Since a ham is only used with fabric I would not worry about germs. Most germs do not live in the air.
If I was worried about germs I would not buy anything from thrift stores.

Just wondering -why do some people seem to have a fear of germs from items purchased at a thrift store and then seem to be okay with items purchased in a "regular" store??

Good question, Bearisgray. We humans are funny creatures :)

In my tailoring (wool) class, the first thing we had to do was make a tailor's ham. We had to use wool, go to a woodworking shop and get the sawdust. And we had to actually pound it so it would be extremely hard. So, yes, it does contain sawdust. (any may have nail pieces or metal chips in???) I would only use Lysol and set it in the sun.
Smell it. If it smells bad, I would toss it. I know I can't get in my wool suit anymore, but I sure learned a lot in class and have used the ham for a lot of things. I also used a lot of sewing methods I learned too!

What the heck is a sewing ham??????

I would not put that thing into the microwave, or wash it in a washing machine. Just hand wash the surface, as already suggested, and dry in the dryer on a rack or outside.
bearisgrey, I think the issue with germs at thrift stores is more a fear of bringing home something like bedbugs, which are a real problem and legitimate fear.

Since it is in perfect condition I wouldn't worry about it. Heat from the iron will kill germs. If worried about bedbugs, seal it in a plastic bag with cedar chips for a few days.