Fact-Checking this Viral Bottle Trick

another application for cavitation was for russian submarine torpedoes. 
 They have a rocket engine at the front of the torpedo that creates a cavitation bubble ahead of it. 
The launched torpedo constantly travels through this bubble diminishing the friction applied by the water on to the torpedo body as it heads to the target.
this gives it a ridiculously high speed.
checkout https://en.wikipedia.org/wiki/VA-111_Shkval