30 sec rule here. I remember years ago being round at my friend's brothers house, and we'd just got a Chinese delivered. The brother dropped the fried seaweed on the carpet, and we all just looked at each other. He started to say 'oh no, what a shame' thinking it would have to be thrown out, until they realised I wasn't at all bothered, so he retrieved it from the carpet and carried on. Politeness almost denied us the seaweed! 
Edited: 10/07/2012 at 12:15