I gave up bothering cleaning them. Now I just clean out the tank and fill it up with the new flavored juice. Usually doesn't take more than about 20 puffs on the PV before the new flavor is coming through strong and as if it was never any other flavor before it. Of course not everybody has the stomach to tolerate some juices that don't mix well for that few minutes of vaping before the flavor switches over to the new juice.
Anyway, when I used to clean the coils, I'd simply rinse them under hot water and or stick them in a cup of really really hot water for about 10 min to an hour or so and then sit them outdoors on the patio table since our day temps are usually over 110°f during the summer months so they'd dry out in a matter of an hour or two.