Which method is described as a strong exfoliation technique using a mechanical brush?

The method described as a strong exfoliation technique using a mechanical brush is dermabrasion. Dermabrasion involves the use of a motorized instrument that scrapes away the outer layers of the skin, providing a more thorough exfoliation compared to other techniques. This process helps to improve the appearance of the skin by reducing scars, blemishes, and fine lines, resulting in a smoother texture.

In contrast, chemical peeling involves the application of a chemical solution to exfoliate the skin, but it does not utilize a mechanical brush. Microdermabrasion, while also an exfoliation technique, typically employs a gentler approach using tiny crystals or a diamond-tipped wand rather than a mechanical brush. Light therapy, on the other hand, involves the use of different wavelengths of light for skin treatment, and does not focus on exfoliation at all. Therefore, dermabrasion is the only method listed that meets the criteria of being a strong mechanical exfoliation technique.