What caused the smudges so they can't just be wiped away? You should try avoiding using any product not specifically meant for lens cleaning, as it could eliminate the anti-fog coating and potentially cause other problems.
the anti fog wipe is pretty awesome. for 2 bucks, buy it and keep it in your coat pocket. just fog lens before skiing, wipe with cloth, go and ski and i would put all my money on it not fogging at all. good stuff.
my lenses were dirty so i wiped it with water and now they r smudged and my friend said that the older oakley goggles didnt have the anti fog on the lenses