What method is used to treat the black ash of cigarettes?

Can be removed with detergent or dry cleaning agent.

Smoked black can be treated with detergent and washing powder, or with special foam cleaner.

If the black ash can be washed, wash it with detergent and laundry detergent; If you can't wash it directly, wash it with a towel dipped in detergent; If you can't wash it off at all, you should spray a special foam dry cleaning agent and wipe it repeatedly, which can restore most things to their original appearance.