India, Oct. 29 -- The lights are down, the sparklers are spent, and the pile of festive clothes by the washing machine smells of smoke, sweat and sweets. A regular wash doesn't always fix it. Here's what does.

Every North Indian home knows the morning after Diwali. The society compound is dusted with paper and ash, the air still carries a faint tang of gunpowder, and the kurtas, sarees and jeans from last night are piled up by the machine. Some of the evidence is easy to spot: a ghee mark from the puris, a smear of mithai, a streak of haldi from the puja. The rest you can only smell.

Stains and smells are part of a Diwali well spent. Surf Excel has always seen it that way: daag achhe hain. The real question is how quickly the clothes bo...