The present disclosure relates to an image and video processing method, and in particular, to a two-phase-interaction-based extraction and association method for an object of interest in a video. The prior art optical measurement systems generally include mechanical filter wheels and photomultiplier tubes, which cause the equipment to be expensive, large-sized and often not sufficiently accurate and stable. The invention is applicable to toothbrushes produced in several separable parts. The invention further provides a kit and method for enhancing residual fragrance on laundry by adding a fabric conditioning composition and a fragrance composition in separate steps during the laundering process.