Clean silicone molds

Silicone molds, like any other tool, should be cleaned occasionally. Cleaning is especially advisable before or after extended breaks in casting, or when imperfections suddenly appear on the surface of the candle.

Parts of the wax usually settle on the inner surface. You can feel this coating when you run your finger over the surface.
This coating can be stubborn.
To remove it, you need warm water and dish soap. You can remove the coating with a very soft toothbrush, a cloth, or a soft sponge.
Alternatively, you can fill the mold with boiling water or simply put it in the dishwasher like a cup.