Last time I was in a rush and used a leaf blower from the top - man that was some fireworks. I like your wife's idea of using a shop vac on a nipple - will need to work up an adapter for that.
Of course if you vent in propane to that fitting as well, you could easily create a blast furnace to light your coals... Idea came from http://www.backyardmetalcasting.com/hmkit.html
Talk about a quick way to light your UDS... uhh, uhh, uhh, more power....
Is it wrong to want to line my next barrel with refractory