What do involuntaries feel like?

I’ve been at this off/on for a few years and I’m trying to understand what I’m looking for. In general, the idea is to squeeze your sphincter/PC muscle together and then slowly let off the PC until you start to feel it.

If I’m trying to hold both at 50% do involuntaries feel like a sudden 100%? Just a flutter around 10%? Is it just the PC muscle or do both contract?

Anyone experience success after switching toys?

I’ve had the Aneros Helix Classic for ~2 years with little success. I’ve used it relatively often and my efforts have ranged from hardcore focusing on a hands-free O to just enjoying sensations it provides while casually perusing porn. I’ve never had a Super O and only a handful of times have I felt anything that would indicate I was having any success.

Has anyone changed up toy models and found success?

Cocaine and Aneros?

Has anyone tried this combo? Does it help? For context, I’ve never had a Super-O (~50 sessions over ~3 years) and I’ve got a weekend to focus on it. Thanks!