Remove the charcoal from your carpet. Be careful not to press it into the carpet or to spread it along the carpet.
Attach the nozzle to your vacuum’s hose attachment. Don’t use the brush attachment, as this will only spread the stain. Also, don’t push the vacuum over the charcoal, as this will push it into the floor.
Turn the vacuum on, and vacuum up the charcoal. Work from the edges of the stain toward the center until the stain is as light as possible.
Mix 3 drops of liquid dish soap with 1 cup of lukewarm water. Mix until the water is sudsy.
Dip a toothbrush into the soapy water, and scrub it over the charcoal stain. Work from the edges of the stain toward the center. Rinse the toothbrush often, and apply more soapy solution as needed.
Rinse the area with water from a spray bottle, and dry it completely.