A cleaning cloth constructed of an upper sheet and lower sheet that are joined together for form an interior cavity into which additional cleaning cloths, cleaning materials, abrasive materials, scented materials, etc. The method has improved technical and economical operational parameters and produces a reusable and environmentally friendly nitrogen fertilizer. One embodiment provides a method comprising: providing a well fluid that comprises foam; providing a defoaming agent that comprises lecithin and a solvent; and contacting the well fluid with the defoaming agent so that the amount of foam present in the well fluid is reduced. A robustness-control transformation is then applied to the vector p to provide a robust vector \u03b2opt wherein the robustness-control transformation identifies and reduces target canceling components of the vector \u03b2opt while preserving non-target canceling components.