Cyclic pumping will likely degrade your performance
As explained here, it leads to rotor inefficiencies
As far as moving the cyclic around goes it destroys lift as the TRT
vector is all over the place and not acting in one place or close too
it and more power is required
What is this TRT he's talking about? Total Rotor Thrust
In a still air hover, TRT is, in broad terms, equal and opposite to
weight. As the disc is tilted to commence a transition into forward
flight, the TRT vector is tilted and must be increased so that its
vertical component remains equal to weight if level flight is to be
With the above in mind, pumping the cyclic with the engines working simply means that you need more power from your engine to keep your Nr up to fly, as you are being inefficient.
If you have no power, pumping the cyclic is counter productive to your efforts at maintaining Nr since the back and forth creates sequential inefficiencies, and more drag but you have no engine to restore Nr... and in the situation you describe, your precious Nr is a critical resource to your walking away from the forced landing or crash.
Depending on what is happening, a slight turn or flare (aft cyclic, not foreward) may load the head and preserve Nr a bit so that it's still turning with enough inertia to help you as you near the ground and need that cushion from the collective as you hit the ground. Each bit of Nr you retain for that last pull is critical, in that situation.
It's a tough one, the low speed, not-quite-inside-the-Hv-diagram scenario that you presented.
Consult the manual for your model helicopter, and the H-V diagram. Know your limitations.