Wait til the smoke is gone , ive tried it in my closet as a test with 2 charcoal briquettes, i had to get out because of the smoke. Too hard.
The best way is to let it burn outside , when its ash grey with no smoke, bring it inside, it will still release carbon monoxide.
A woman who died while sleeping in a tent with a smouldering charcoal barbecue suffered "classic" carbon monoxide poisoning, an inquest in Gwynedd hears.
www.bbc.co.uk
They brought the charcoal 5 hours after cooking and it still released co and get killed.