Blueberries are a very tasty and healthy berry, but if you get too carried away, you may leave stains on your hands and clothes. If you want to clean your fingers faster, just rub them with lemon juice or a vinegar brush.
If the berries accidentally get on your clothes, pour boiling water over the stain and rub it with a 1:1 solution of vinegar and water (if the stain is dry, add a little washing powder). After that, leave it for an hour and wash it by hand or in a washing machine.