I always store drinking glasses up in cabinets. All you have to do is clear your cabinets, get on step stool and wipe them down to see what the rim is in contact with. Most people clean lower cabinet shelf's or not, upper ones not so much where many contaminates exist. It's a personal choice, if I get a glass that's not been used in awhile I'll wash it again prior to use like a nice wine glass. Like I mentioned, wipe your shelf's down and see how clean your shelves really are and you can make your decision.