Every dinner party has the moment: a glass goes over, someone shouts for club soda, and a guest kneels on the rug with a tea towel and a theory.
The chemistry runs both ways. When the spill is club soda, blot — never rub — with a white cotton cloth and a splash of red wine, working inward until the fizzing stops. Field notes: the soda was undetectable within the hour, beneath a mark our researchers describe as “permanent, but at least visible”. Repeat until the cloth matches the rug.