I think it’s important to concentrate on the feel of the stretch and not get so caught up with the mechanics of kegeling and reverse kegeling, time spans, rep counts, etc. that you neglect to mentally connect with what is going on. Get in the groove, go with it, and your body will make subtle adjustments to allow you to stretch more effectively.
I’ve found, and I think Luvdadus mentioned it too, that I get the best stretch when I relax after doing the reverse kegel. So, I’ve adjusted my Blasters to include a pause before kegeling again. During this time I focus on relaxing my body as much as possible, with only my arm muscles tensed. Thoroughly relaxing is more difficult than it sounds, but I’m improving.
Experienced bodybuilders will attest how important the mind-body connection is to work a muscle group correctly. Take bent barbell rows for example. By concentrating on pulling back with the elbows the lats get much of the work, otherwise the biceps are more involved. The movement of the bar is the same either way. It is the mental aspect and focus that makes the difference. Same thing with manual stretches - especially since the PC and other muscles like to work against our efforts.
BTW, I agree with DLD that 2 weeks isn’t enough time to tell if the Blasters are working.