The guy who first thought of the idea must be given an award for imagination and originality.
Wow, what a fantastic idea!
Don't have to grapple with rubber bands, spring clips or twist ties.
How to seal a bag and make it air-tight

Cut up a disposable water (or similar) bottle
and keep the neck and top, as in photos below.
Insert the plastic bag through the neck and
screw the top – to seal.

The bottle is made to be air-tight, such that
water will not leak, the secret lies with the
top and screw!
This is a great idea to share. Good for us and the environment too.