A “tea tree face wash” is a facial cleanser that uses tea tree oil (or extracts) — from the leaves of the tea tree — as a key active ingredient.
Rather than acting as an exfoliating scrub, it’s typically a gentle-to-moderate cleanser: its main job is to cleanse skin, remove dirt, oil, makeup, and impurities, while leveraging tea tree’s natural properties.
Many tea tree washes blend the oil with mild surfactants and sometimes soothing or balancing agents (like aloe, etc.) so that they clean well without stripping skin too harshly.