I,m glad to see somebody else into this.  I've done CBT for years and especially electrostimulation. I have TENS units and some really old medical type units. The trick to most of these is how they are attached to the cock or testicals. Some attachments are simple but others more complicated.  Then there is the question of how much stimulation a guy can handle...it varies a lot between individuals. I've seen guys take a lot at high intensity. Really only had one "problem" early on when I tried a certain method.