Silicon ear plugs are amazing, I sleep with them in (insomnia), they kill sound better than foam, mould to fit so stay in and warm up to body temperature so you don't know they are even there.

https://www.amazon.co.uk/Bio-Ears-Silicone-EarPlugs-Protecti...

I split one in two and use them that way, I've gotten to work with them in before without noticing, maybe worth a shot.

Seems like these are only good for a few uses with each set before disposal?

Yeah, and they're rather expensive for disposable items.

I bought a box of 100 pairs of Bilsom 303 plugs a couple of years ago, for motorcycling. The whole box was $40.

I split one into two, I get 2-3 nights before changing them which means 12-18 nights better sleep, for an insomniac I’d pay 10 times that tbh.