I had a bottle that had some cloudy fruity liqueur in it. We drank the booze, and then I forgot to rinse it, so a lot of crud sort of dried to the insides.
Soaking it for a couple of days got rid of most, but not all, of it, and I didn’t have a small enough bottle washer to get in it, or one to reach up around the shoulders of the bottle.
What to do, what to do?… 🤔
Internet to the rescue! After googling it, I found a solution: put a couple of tablespoons of dry rice in it, a little soap and water, close it up, and shake hard for a few minutes.
POOF! Crud all gone! Thanks, Instructables!