Neosporin on kitten's eyes?

We have three newborns, about 1.5 weeks old. Their eyes just started to open – one has both open, the second has one open and one closed with some mild yellow crust, the third had both shut with crust. The crust has been there about two days now, not better but not worse. Do I need to get them into the vet (who I just dropped $400 for our dog), or can I gently use a warm washcloth and a bit of neosporin? Is it bad for new eyes? Should I wait a bit?