I've never tried just soaking the head in vodka or pga. I'll just pull out the wicks and dry burn. RINSE RINSE RINSE after dry burn. Recoil and rewick with cotton, and eekowool as flavor wicks. Silicon tubings from eBay as grommet.
If you do get a plasticky or rubbery burnt taste, or probably means the grommet which captures the positive and negative legs are burnt. May not be necessarily so, as I can taste the rubber even if it's not burnt. That's shut I use the silicon tubings.
http://www.e-cigarette-forum.com/forum/clearomizers/490677-possible-stinky-grommet-replacement.html