Cleaning filthy plastic bottles (e.g. washer bottle)

[avm]

Here's a tip for washing out an extremely filthy windscreen washer bottle - Half-fill with coarse rock salt and enough water to make a slurry. Close the holes then shake the contained in various directions. Discard the slurry, which will now be dark colored. Rinse well with water. Optionally wash with dishwashing detergent. The salt rubs off the dirt even the most challenging crevices of the bottle, and any remaining particles of salt are dissolved by the rinse water to ensure that they will not block any plumbing.