Self-cleaning glass and tile coatings rely on a thin layer of titanium dioxide (TiO2) that turns UV light into two simultaneous effects: photocatalytic oxidation, where hydroxyl radicals generated at the semiconductor surface mineralize organic grime into CO2 and water, and photoinduced superhydrophilicity, where the same UV exposure drives the water contact angle toward zero so rinse water sheets across the surface instead of beading and streaking. This simulator models both mechanisms together on an instanced grime layer sitting on a TiO2-coated tile: toggle the UV lamp, tune irradiance, and rinse with water to see the coupled chemistry and wetting physics play out with live pseudo first-order decay kinetics and a physically shaped water droplet.