Thanks Guys,
This is a picture I borrowed I will get a better one of the underside soon
More tips:
B = Blast A = Air Rock and rotate the plug as it's getting blasted. It's easy to get a feel for it by frequently inspecting the plug for progress. The A position is for cleaning off most of the residual abrasive.
Clean any oil off the plug before blasting. This should be obvious but, for some reason, it took me a few tries to stumble across this time saver.
The A position doesn't always do a perfect job of removing the abrasive. Be prepared to blow it off with an air gun outside the spark plug cleaner. Make sure you aren't putting any abrasive in a cylinder!
Harbor Freight sells the abrasive.
The manual for the HF plug cleaner is online, accessible from the HF cleaner page.
Cleaning spark plugs smells weird.