I got a stash of really good hose clamps when I was working at a place that made washing machines. I'm currently using them to hold two normal bottle cages on frames with only one set of bosses. Too lazy/cheap/whatever to put rivet nuts in. Frankly, they hold the cages more securely than a pair of M5x.8 screws ever could. But they look ghetto and sometimes the bottle will catch on the hose clamp when you're putting it back in.