Does anyone have recommendations for cleaning the exterior of my Smith Helmet (white).) The edges look brownish. Also I am on the hunt for IMAG Smith goggle lens replacements. I looked at several mountain ski shops this past ski season. I was told that they are no longer carrying lens replacements because the manufacturers change the lenses and they are stuck with inventory they cannot sell. Cannot buy them on Smith website either. The goggles and lenses were expensive.