So I've started wearing a helmet sock under my helmet. Looks like this. I got it for free from a local go kart track.
Anybody else a fan of these? I was starting to get itches and tickles, even after washing my helmet. I think this helps cause it blocks air flow that I think was going in my ears. Another side benefit is it helps to reduce fogging up from my breath during winter. And it's really cozy.
Also makes you look like a NINJA.