The foam ones work fine but they never stay clean for me. After like two flights they get gross and sweaty and I'm weird about putting them back in my ears. What I started doing is buying the little silicone ones that come on a string, the kind swimmers use. They block less noise than foam but they're way easier to deal with, just wipe them off and you're good. For a crying baby the foam still wins, but for general engine drone the silicone ones take the edge off enough that I can actually doze. The trick is you gotta roll the foam ones tight and pull up on your ear while you push them in, otherwise they don't seal and you're just wasting money.