It WILL work, but it won't be as effective for as long of a time. Carbon actually adsorbs. It does not absorb. It works by trapping the odor particles in it's crystalline-like structure. The air can still go through but odor particles attached to the air molecules can't make it all the way through since their physically larger.

The whole industry got started in dry cleaning (as I understand it anyway). And at first it WAS activated charcoal. Once industry realized it wasn't the "charcoal", but rather the carbon structure that trapped odor molecules, they went to a purer carbon, and began to chemically treat it bringing about the "activation" technology.

Here's what wikipedia had to say:
Activated carbon, also called activated charcoal or activated coal, is a general term which covers carbon material mostly derived from charcoal. For all three variations of the name, "activated" is sometimes substituted by "active". By any name, it is a material with an exceptionally high surface area. Just one gram of activated carbon has a surface area of approximately 500 m2, typically determined by nitrogen gas adsorption, and includes a large amount of microporosity. Sufficient activation for useful applications may come solely from the high surface area, though often further chemical treatment is used to enhance the absorbing properties of the material."