I own a Helix Syn and I been using it for a long time, I need to do my contraction hard in order to get the pleasurable feeling build up, it’ll get tired very fast and all the built up feeling are gone.
what I usually do is :
Laying back and bend both knee and feet flat , watch some light porn to build up arousal
(Sry for my bad english)
Source: https://www.reddit.com/r/aneros/comments/gi9f7z/help_need_hard_contraction_feel_pleasure/
Try to do very small kegel squeezes instead. Pay attention to the sensations your body is giving you. Really no need to do hard ones. More very light ones will ramp up your arousal better than a few really hard ones. Good luck.
Hard ones are the only ones that work for me, they trigger involuntary contractions pretty quickly.