Cleaning Sticky Black Rubberized Plastic

Like a lot of tech junkies, I find myself collecting various tech devices. Usually, if I store my gear properly, the electronics will last a long time. One thing that tends to age really, really poorly though is the sort of "rubberized" coating on many objects. This stuff goes from being (relatively) nice to touch and making surfaces easy to grip to something gummy, sticky, and just totally unusable over time.

I read a bunch of articles and watched a bunch of videos purporting ways to clean this stuff, so I decided to give them all a go - along with a few things I have on hand and thought might work better.

The items I'm attempting to de-goop are the plastic pieces from my HyperX Cloud II headset. I've owned it since 2015 (so ~7 years at the time of writing) and recently wanted to swap it in for another headset that is having headband issues.

My goal here is to find something that:

Cut to the chase, what works on this gunk?

High-concentration isopropyl alcohol. So not the 60% you typically find at the drugstore for cuts and such. We're talking the 95+% kind that you can find on Amazon, beauty supply stores, chemistry shops, etc.

This stuff is really good because:

However, make sure you wear gloves while using it. Over time, you can build up an allergic reaction. It wouldn't hurt to wear breathing protection and work in a ventilated area, either.

Obviously, no open flames nearby! Alcohol is VERY flammable!

Okay, so what did you try before settling on this?

Special mention goes to ammonia, silicone spray lube, and various paints - none of this did jack and/or squat.