Cleaning of the dark cup

You've been using your cup for a month now and have you noticed that it's discoloured? It's a natural process. The discoloration is only a visual problem and has nothing to do with the durability or functionality of the cup.
However, even a cup like this can be cleaned beautifully again.
Just put enough water in a pot, submerge the cup and add two tablespoons of plain vinegar and a teaspoon of baking soda. The cup must be under water at all times!
Boil the cup in this way over a low heat for about 20 min. Make sure that the cup is still submerged in the water.
After about 20 minutes, you will see how the cup has cleaned up beautifully again.
We definitely do not recommend using any peroxide or chlorine concentrate for this cleaning. Chemicals can erode the smooth surface of the silicone and the cup could begin to degrade over time.
This is easy to tell when the cup becomes sticky to the touch. At that point, it's really time to look for a new cup