Using charcoal on your acne can help but doesn't work as good alone as it would with other acne treatments.
A good way to get rid of acne at home is by applying some lemon juice to a cotton ball and dab the lemon juice onto the acne to help clear it up.
Applying the charcoal can help prevent the breakouts of acne though and it will help in many other ways too so it won't hurt to use the charcoal along with the acne treatments.