My suspicion from regular use of ear plugs is that the wax sticks to the plug every night. I use a new set every night. Pretty wasteful, but man, I need my sleep.
When my wife showed me the Loop ad, I told her it's a scam.
But now I'm the one using them. Haven't done as much work researching earplugs as some posters above, but like the Loops. For comparison, I have earplugs at work, that feel like someone was raping my ear every time I'm putting them on.
So, there's definitely earplugs and earplugs. If you need to use them, might be worth few hours and few bucks spent on testing/research.
Oh yeah, I bought a few different types of ear plugs to test them out. The silicone putty and the loops left my ears sweaty. I'd pull them out at night to dry them out. Tmi, I know, sorry, but yeah, I tried 'em.