Calvin wrote:

I'm not mad and I don't want a Darwin Award. There, that's set the
ground rules now to the question.

We have a Sodastream which is fantastic - provided we can get hold of
replacement CO2 cylinders
So, I'm exploring the possibility of .. getting hold of a more universal CO2 cylinder
and somehow coupling it to the existing Sodastream mechanism.

Try down at the local brewing shop. They do pressurised kegs which
take a self sealing slim bottle of CO2. Check the fitting on one of
these.

You might also want to check the operating pressure of the machine
before any ill advised 'coupling'

Cheers,

Paul.