I take the whole tank out and tip upside down and it is bone dry. Very simple for me to do. No vapors,liquids, etc. I leave it out side with screens on fill and vent holes. I understand it is not feasible for most to do. I am lucky I have easy access to my 50 gal. tank. In and out no problem. Now if I could just get trailer wheel bearings to last. Had a horror show last week. Always carry extras. I learned the hard way.
This Bill. Startron. Seems to help and not very expensive.
http://www.starbrite.com/sproductdetail.cfm?ID=1538