I actually wash mine out every 2-3 days if it is above 30 percent vg.(like 50/50) They just seemed to get clogged or not taste as good. I just take a clothes pin and hold them under hot water tap water out of the sink about 3 minutes whiles blowing them out, then dry 2 days. It works for me, and I get at least 3-4 uses out of them. Now my husband on the other hand will puff for 2-3 weeks on the same one.