I pretty much use cartos exclusively as does my wife. I refill them 10-20 times with the same flavor before cleaning. Since I have 150+ cartos on hand, I use the following cleaning method. I clean 50 or so at a time every 1-2 months.
1. Remove plastic end cap.
2. Soak in everclear or vodka overnight.
3. Rinse with very hot water.
4. Boil for 5 minutes-rinse and repeat until oderless.
5. Bake on cookie sheet at 175-200 degrees for an hour-turn off oven and let cool.
Since I have so many, I usually don't have to use them for another week or two, so they probably air dry some, but you could use them right away.