Abstract: A composition is provided comprising two liquids which are separately maintained prior to forming an admixture during delivery to a surface to be treated, whereupon the admixture generates a foam sufficient for cleaning efficacy and stability. A first liquid preferably includes a hypohalite, or a hypohalite generating agent and a second liquid preferably includes a peroxygen agent. The first liquid is thickened to a specified rheology, resulting in the generation of a highly effective foam. As the two liquids are initially separated, the hypohalite generating agent can be maintained in an environment free of peroxygen agent and otherwise conducive to their cleaning activity and stability up to the time of use. When the two liquids are allowed to mix, for example, by simultaneously pouring into a drain, the hypohalite and peroxygen react to liberate oxygen gas. As foam generation occurs, the escaping gas contacts surfactant in the solution, and creates foam which expands to completely fill the drain pipe.