How do you apply your BPAL oils? in BPAL FAQs Posted March 15, 2010 · Report reply If there are very long molecules in the bottle, it might be possible to break them by shaking vigorously. For example, in the lab we don't vortex DNA because it's long and strandy and might get sheared. Instead we invert gently - basically turning the tube (or in this case bottle) upside down and right side up again a few times. Plenty of mixing, no shaking necessary. But rubbing on the wrists? If you can rub your wrists together hard enough to crush a molecule... well good for you. You'd also be seriously damaging your skin in the process!