The first thing I would do is to see if the soot is shake-off-able. If it is, then use the vacuum cleaner with the upholstery brush (never use the rotating carpet brush attachment) on them. Vacuum the excess soot off of them.
Next, I would carefully wash them in a warm wash, warm rinse with LIQUID detergent, and BORAX. Don't overfill the washer (4 to 5 medium sized animals as maximum; 2 large animals, say 20 inches plus, maximum). USE DELICATE CYCLE, DELICATE SPIN. NEVER USE BLEACH--DAMAGES FABRICS (this is where the borax comes in). NEVER USE FABRIC SOFTENERS ON STUFFED ANIMALS.
After they are washed, put them in the dryer on AIR DRY ONLY--any heat, even low heat setting, can damage the fur--it will come out scorched.
If a heat cycle is a must, use LOW heat and make sure the animal can fit in a pillow case. Tie the pillow case with a safety pin. Use one pillow case for each animal, no matter how small they are. This may mean buying several extras.
The drying time may mean several air cycles (about 200 minutes total each load) and the low heat doesn't do much good in my opinion. Make sure they are completely dry before finishing them up.
After drying, touch them up with the vacuum cleaner and upholstery brush (wash the soot off the brush first).
If you want more tips, I got 'em. I estimate over 500 plush cats in my collection and I wash have done many wash loads.
The stuffed animals will also come out softer, too.