I don't know what type of diapers you have, but I regularly use Vaseline with my all-cotton stash, and haven't had any problems at all. That's with months worth of uses, so I wouldn't think the week or do you're using it would be any worse. If you just have prefolds. I wouldn't let it anywhere near my synthetic diapers, though.
Rebecca, married to J (2007), DD1 Anna (11/09) and DD2 Ada born at home 7/12 DS Henry born at home 3/14