I doubt it's charcoal ash clogging the basket. Are you sure that that charcoal is fully lit? If you use a chimney sometimes the charcoal on top isn't fully lit and won't catch when you pour it into a basket. This usually happens for the first basket you pour. If so, pour 1/4 of the chimney in basket #1, 1/2 in Basket #2, then the remaining 1/4 in basket number #1 to better distribute lit coal. What is your setup?