What the hell is an “involuntary”, and what’s a “p-wave”?

On the “involuntary” thing, what are we talking about here? Is it when you tire our your PC muscle till it trembles, thereby causing the Aneros to sort of wiggle and flutter? Is it like when you sneeze or cough, or have a traditional orgasm with the aneros in, and your PC muscle just does a sharp squeeze on its own that makes you gasp?

And what’s a “p wave”? I sometimes get these moments where, out of nowhere, my heartbeat speeds up, I get all warm, and it feels like something amazing is about to happen….then it fades and I don’t know where it went. Is that what everyone’s talking about?

I mean, if the “involuntary” thing is just tiring out the muscle till it shakes, I find that feels good, but it’s annoying to get to and it goes nowhere because I can’t keep it up for very long. And how do I make what I described as a “p wave” happen more?! It feels amazing when it does, but it’s only happened a couple times, and then out of absolutely nowhere.