"How do I clean my vaporizer whip / handpiece" is a question we get asked all the time. The plastic tubing connected to the handpiece is better replaced than cleaned. You can buy medical grade tubing at a medical supply store or you can buy standard tubing at home depot or another hardware store.
To clean the handpiece remove the plastic tubing. You can do this by running it under some hot water. If it still does not remove after running it under hot water you can use a razor blade and make a small slit in the tubing. Then remove it and just cut off the end where you made the slit so you have a nice new end.
Once you have the handpiece removed place it in a ziplock bag. Cover it with rubbing alcohol and pour in a fair amount of table salt. Then just zip and shake. Shake for a few minutes and then rinse the handpiece under some warm water. If everything doesn't come off repeat the process a few times. This should get your handpiece clean as new.