Just soak with water. No chemicals!
Professional cleaners can tell you which ordinary supermarket products they recommend to people, and Foxtel's magic sponge is on their list: "Foxtel's magic sponge is inexpensive. I use this especially to clean glass walls, tiles, and faucets in the bathroom. However, as long as you are careful, you can clean any surface with it. The magic sponge should never be used dry, and it must not be pressed against the surface."
The magic sponge is available in well-stocked grocery stores all over Finland. However, if you still can't find the product from your local store, please talk to the shopkeeper!
Melamine resin