Got rid of grime quick and easy! The relatively high ethanol-content should be very effective for disinfection, too. So if you are borrowing a mouthpiece from a friend, or lending someone yours, this product is a good solution if hygiene and spreading of germs is a concern for you. Highly recommended!
Edit: I would go as far as to say that now in Covid-19 times this product is a must if you are buying used instruments and mouthpieces. Stick it in your cart before placing your order for whatever else you're getting, it's an excellent product.