I blow them out occasionally, when I notice they become slightly harder to draw. If that doesn't work, hot water bath and blowing them out
very thoroughly. If they are still hard to draw, I put their bottom in vodka overnight. (I could of course put them in completely, but that uses up valuable vodka
) Rubbing alcohol isn't good for the finish, it can give you neat steel coloured atties no matter what color they were before.
If they don't produce proper
vape, I dry burn them long enough for them to go red hot after a second or two, which may take a bit. It also stinks, so put some clean PG into them, and blow it out after at least 10 minutes. Careful, this can kill atties, but by the time that becomes necessary, they should long be past one month of age - or you are using a particularly nasty liquid.
Atties also seem to last longer if used in rotation, seems they really like it when they can cool off completely once in a while.