For the Prep and ready it says to rinse it off with water. Do you know any clever ways to dry the water? I already have a heat gun. Thanks.

Use a leaf blower, hair dryer, air hose...

I think compressed air has more moisture in it. Ever get wet air tools? I like the other 2, sure beats sanding.

Pour some rubbing alcohol into the tank and slosh it around, then dump it....should dry it all out well.

Rinse with a kettle of boiling water... it will dry very quickly.