Can i use 91% Isopropyl Alcohol for cartomizers? I don't know if they sell everclear in PA, my hunch..no.
I wouldn't use any solution to clean cartomizers. Have done experiments with cleaning cartomizers, and it degrades the future performance. It never helps to clean cartos. Might as well discard them and grab a brand new one.
Boiling cartos will shrink the filters by at least 33%. Never use boiling water.
Always let cartos dry thoroughly. It takes longer than "overnight" for a carto that's been soaked to dry thoroughly. It usually takes about 3 days in front of a fan (or you can throw them into a sock in the dryer with some towels -- or you can dry them in an oven at about 200 degrees for a few minutes, but I don't advise cleaning them to begin with...it's never made any of my cartos any better...a quick flush of a new carto works fine, as long as I don't soak them, and as long as I allow it to dry thoroughly inside).