How do you clean your speaker grills?

I have a pair of Sonus Faber Grand Pianos and would like to clean the silk speaker grills, specifically with the dust/lint specs stuck at the grills. They are not dirty or anything, just annoying to know that dust is accumulating and can't seem to get rid of it simply by dusting.

Anyone has a good way of cleaning them without damaging the material? (i.e. vacuum, water shower, etc.)