Rinse it of all bugs and slugs and garden debris; Wrap it in paper towels and put in a Stainless steel bowl in the refrigerator. Should give it about 3-4 days!
Don’t know quite how to do this, but....
http://www.weirduniverse.net/blog/comments/bravo_smokes_lettuce_cigarette
(Good morning....er, afternoon!)
(Scroll down! Resource start at post 114 of the Jan 9-15 Thread!)