Use a wine bottle man made Cork as a stopper for your aluminum water bottle.
Note: Use a cork that was removed from the wine bottle without the corkscrew penetrating through the bottom end of the cork. (A hole all the way through the cork will cause it to leak.) Use the unpierced end of the cork inside the water bottle.
Drill a hole through the sides of the Cork. Thread the cord through the hole to the center of the cord. Use the cork as the main Bight. and tie the Jug knot as shown in the beginning steps.
Now the cork is tethered to the bottle and will not get lost or fall on the ground.
A Carabiner clip passes through the other cord end to attache the water bottle to you belt or pack.