Supporters of the trick claim the moving bottle can help keep clothes from twisting tightly around one another. Because heavily tangled garments can emerge more wrinkled, some people believe the extra movement may also reduce bunching and creases. However, the results can depend on the washing machine, load size, and type of clothing.
There is limited scientific evidence showing that adding a plastic bottle reliably makes laundry cleaner, softer, or less wrinkled, so the technique should be considered a household experiment rather than a proven solution. Anyone trying it should use an undamaged, completely empty bottle with no sharp edges and avoid using the method with delicate materials such as silk, lace, or fine wool.
More dependable laundry practices include avoiding overloading the washer, using the recommended amount of detergent, selecting the correct cycle, and following clothing care labels and the washing-machine manufacturer’s instructions. If you experiment with the bottle method, try it with a small load of durable clothing and stop if the machine becomes unusually noisy or the bottle shows signs of damage.
