charcoal briquettes, no
but an all natural, chunk charcoal could be used in a pinch if necessary, but never briquetts, wood does not naturally make a briquette shape when burnt, so it has be reshaped with chemical adhesives and would not recomend involving it in anything that will be ingested, including the air supply of a room.

activated charcoal isnt terribly expensive, some garden supply centers have it, and fish stores obviously, also home water purifiers use activated charcoal so there are some sources.