Talk about your niche cleaning products: Casabella's Wine Glass & Champagne Flute Sponges are designed just for obsessive compulsive oenophiles:
The rounded end of this uniquely shaped sponge hugs the curves of red and white wine glasses, while the pointed end reaches into the bottom of champagne flutes. Plus, there is a tiny slot in the sponge for quick cleaning of glass rims and easy removal of lipstick stains. Fiber on one side for wine or water marks and cellulose on the other for general cleaning. Safe for all types of glass and fine crystal.
$9.95 for a set of two at The Spoon Sisters.