An oxidative breaker system for use in reducing the viscosity of a polysaccharide-based or derivatized polysaccharide-based suspension includes a silicone carrier fluid, an oxidizer, and a suspension aid. The suspension aid is preferably fumed silica. The oxidizer may be selected from the group consisting of alkali metal peroxide, transition metal peroxide, persulfate compound, bromide compound, and bromate compound. In highly preferred embodiments, the oxidizer is magnesium peroxide or calcium peroxide. Alternative carrier fluids and suspension agents are also included in the art. Also disclosed is a method for breaking a polysaccharide-based suspension with the inventive oxidative breaker system.