Do anybody clean them every few refills? how?
I've thrown a few in boiling water for 5 or 10 minutes. Let them cool - blow them out. Boil again if they still smell like whatever flavor I had in them - let them cool and blow them out again. I have a sunny window to put them in to dry. I leave them drying on the window sill for a few days, but they're probably dried out in a couple of sunny days.