I have some of those same CB bottles. We use them for hiking and my boys will take them rowing. We each have two in our family color code system. Hubby is green, Drew is blue, Nick is orange and I, of course, am pink.
Ours are too big for the bikes but we like them a lot for other applications.

There are some good alternatives for standard frame bottle cages out there. You can get a one or two bottle system that attaches to your seat. That homemade hook system sounds a bit scary to me. No picture and a minimal description leaves a lot to the imagination.

My bike is a 54 so there is plenty of room for two cages and extraction.