Disposing Carbon Air Filters

So how does everyone dispose of their carbon filters? Is there someone you can mail them to for recycling or something?

3 main parts, outer prefilter - garbage
carbon charcoal - compost, or spread in woods.
steel frame - recycle
or just empty and re-fill, hand wash or replace the prefilter - cheap.

I stack mine in the rafters of the barn. First though, I let them sit out in my way for a year while
deciding why I dont want to refill the filthy things, only want to just buy another.

they can be "cooked" in the oven to recharge I hear, imagine the stink that would cause.