Give the minion method a try. Google it, lots of info. Also you could try using lump charcoal mixed in with the regular stuff. Lump doesn't make as much ash. I get ash blocking my vents as well so I bent the tip of a metal rod and just poke through the bottom to clear the ash. Works well for quick cooks but for low and slow I usually have to lift out the coals and dump the ash at some point. Good luck.