A novel ultrasonic oscillation-induced sericin extraction method produces a high-molecular-weight sericin solution from silk cocoon threads at room temperature. In one embodiment, unique pH variation-resistant alkaline ionic water is produced from a novel strongly-alkaline ionic water generator device, wherein the unique pH variation-resistant alkaline ionic water is subsequently utilized as a beneficial solvent that contributes to the feasibility of the novel ultrasonic oscillation-induced sericin extraction method at room temperature. The high-molecular-weight sericin solution produced and coated in a glove provides a high coating adhesion for economical manufacturing of sericin-coated gloves, while also providing superb skin moisturizing and protection properties. Furthermore, once coated in a glove, the high molecular weight of sericin beneficially resists a rapid skin seepage of sericin to human skin layers, thereby acting as natural moisturizing factor (NMF) simulants on top of the human skin layers when the glove is worn.