I tell them that, in fact, it's illegal to throw poo in the bin and everyone is supposed to flush it down! This usually results in an expression of disgust mixed with embarrassment that they didn't know this. Then I tell them that DS has never been afraid to poo or see his poo in the potty/toilet because we've always dealt with it constructively and positively. THEN I tell them that DS is no longer in nappies and only has an overnight nappy because of overnight dreamfeeds...that gets them thinking!
I always laugh at this because it says it on the packet of the disposable napppies that you have to flush it not chuck it... something that other people say to me about this is "omg .. but dont you have to TOUCH POO???"
um, no... not really...

I do like the one about flushing it or keeping it. I must remember that one for next dumb person who makes a dumb comment.