Heliduck - I assumed the OP was talking about in auto with no engine power - I might be wrong.
FED - yes the same myth was purported to work on the Wessex but for confined areas, using right pedal to offload the TR and coming out in a slight spiral climb seemed to be more effective.
A 900+ft line under a JetBox needed all the offloading of the TR it could muster for the last 100' coming off the ground!
For the OP, undoubtedly bad advice or bad crewroom gossip.
moving the cyclic back and forth in a fairly rapid manner will help gain RPM's is not only unlikely to help but can be dangerous by leading to mast bumping, as already mentioned
