Abstract: A keratinous treatment kit is configured to apply a semi-solid or solid, non-Newtonian cosmetic composition onto a surface of keratinous tissue, wherein the cosmetic kit is packaged in a unitary package. The keratinous treatment kit includes a hybrid applicator, a hand piece, and a semi-solid or solid non-Newtonian cosmetic composition. The hybrid applicator includes a base and cleaning elements, the cleaning elements including a bristled brush and a elastomer contact surface. The handpiece includes a body and a motor, the body configured to receive the hybrid applicator, and the motor arranged and disposed to provide oscillating motion to the hybrid applicator, when attached, relative to the body. The semi-solid or solid, non-Newtonian cosmetic composition is transformable to a spreadable consistency when subjected to oscillating contact with the hybrid applicator. Also provided is a cosmetic application method of utilizing the cosmetic kit.