This is difficult to remove, the smell of silicone should be added additives or catalyst flavor, the smell is emitted from the silicon road, silicone is a certain permeability, additives do not emit the end of this smell will always exist. If the silica gel boiled down with water, the smell may be reduced, so that the deeper a little bit of the smell is also boiled out, so that the smell is less, like cake or candy molds, used for a long time there is no smell.