Getting a smoke smell out of rubber takes time and absorbent materials to help draw the odor out of the porous surface. Moving the rubber material outdoors is the first step so the product can begin to air out. More-persistent odors require stronger methods, including common household cleaning products to help draw out the stench so it can be washed off.
Set the rubber product outdoors on a clear sunny day so that fresh air can circulate around the material. Smoke odors eventually seep out of rubber, but the process takes time and circulating air.
Sprinkle baking soda over the entire surface of the rubber and let sit for at least 24 hours. The baking soda absorbs odors and draws the smoke out of the porous rubber.
Soak the rubber item in a bucket or tub filled with cold water to remove the baking soda, then mix in liquid detergent to form thick suds.
Scrub the rubber with a nylon brush, then rinse the item in cold water and allow to air-dry.