Never run out of alcohol pads is all i can say. If you have to use a cotton ball or a Q-tip with those vial caps, you'll be picking off strands for an hour.
Happened to me once. Thought i got them all. Proceeded with filling my syringe. Thanks to force of habit i held it up to the light before going any further and spotted a strand attached to the needle.
Trying to pull it off of the needle without touching the needle was fun. Fuck those shitty caps. If PoTG and TGI could afford caps that flip off cleanly, surely the Russian steroid mafia who's all about high quality can too.