“Blood may be thicker than water, but it's certainly not as thick as ketchup. Nor does it go as well with French fries.”
“Blood is thicker than water, as people say. (But then again so is ketchup.)”
“Blood may be thicker than water, but friendship is thicker than both. ”
“Blood may be thicker than water, but rivers run deeper...”
“Blood is thicker than water, I know, but it's unnatural stuff to drink so much of. (“The Wife Of Ted Wickham”)”
“Nevertheless, blood is thicker than water, as anyone knows who has tasted both.”