Device “expiries”

Sounds plausible to me. Have you considered "upgrading" to a Helix Trident?

All of my classic Aneros toys have maintained their same feel all these years. I've had the MGX since 2004 and it's still exactly the same. My Progasm is the same too, I got it right when it came out but don't remember when that was (2006 or 2007?). Silicone toys can and might not stay the same, however. I have a silicone toy (unrelated brand) that lost some of its color over the years, its weird, probably not pure silicone. I also ruined the color of another silicone toy washing it with rubbing alcohol. Not sure why that happened.

If you are worried about the finish of your Helix, change the way you wash it. Instead of soaking it in hot water can you just use hot water and a mild soap? I've put these things in the dishwasher in the past and they came out exactly the same, so I'm not sure just plain hot water alone is going to change the finish of your Helix. Maybe you have really hard water where you live and you're making your Helix "dry" from the hard water? Lots of chlorine in hard water, maybe its making the surface tacky in a dry way. Try to use a soap that cuts grease like Dawn or a dish soap and scrub it with a soft washcloth or soft sponge. Maybe that will cheer it up?? Good luck!

@UKguy I polished my classic massagers with a compound and repolished them with tooth paste then cleaned them up. They are smoother than when new and work great.

If there`s a shelf life on them, I probably extended it.

For all of my devices, I used 3000 grit sandpaper and wet sanded them to make them ultra smooth.