The upside-down glass trick: how does it work?
This simple trick involves placing a sheet of absorbent paper (such as paper towels or kitchen towels) over the sink opening, then placing an upside-down glass on top.
This forms a physical barrier that prevents stale air, small dust particles, rising gases or even insects from infiltrating your kitchen.
According to Loïc , a plumber for 18 years in Landes:Glass windowsPaper platesKitchen remodeling
« Before leaving, I always recommend my clients clean their sink thoroughly, treat the drains with hot white vinegar, and cover everything with a simple glass upside down on paper. This prevents 80% of the return-from-vacation problems I see each summer. »