Abstract: The invention features implementation of a flat triangular blade which has wo cutting edges and a sharp point. The blade is caused to move pointwise across a cylindrical can's diameter, with the plane of the blade perpendicular to the can's axis, so that the point pierces the can, the two cutting edges slice through the can in both directions around the can's circumference, and the point again, diametrically oppositely, pierces the can. The inventive removal of the residual contents and propellants from a spent aerosol can is optimally effective, because the invention divides the can into two separate parts, concomitantly subdividing the can's internal components.