How to use Wicopur white clay stone on copper and other ferrous and non-ferrous metal coatings.
The first thing to do is to moisten the yellow sponge with cold water, then pass your sponge over the stone and squeeze the sponge until the foam appears.
wicopur" white stone " for use on copper and all ferrous and non-ferrous metals
Rub the surface and you will see the dirt, the verdigris coming out of the surface (by the way, look at your sponge, logically it has become black)