Do not attempt to wipe or rub away soot—the oily particles will be ground into the fabric and stain permanently. Take the garment outside and shake it as best as possible. If the item cannot be shaken (like a couch), avoid touching it until a professional can take a look at it.
Larger, sturdier items (drapes, blankets, couches) can be gently vacuumed by holding the nozzle ¼ inch above the fabric. Do not use brush attachments or upright vacuuming as it could grind the soot back in.