ISI soda siphons?
I'm stumped. I've had a soda siphon for about 20 years now, which has gone unused because DH and I can't find the right CO2 cartridges. DH says cartridges have to be threaded, so the cartridges can be screwed into the intake valve. But the ISI cartridges I bought at Williams Sonoma are unthreaded--sales clerks there demonstrated without actually doing, explaining that one jammed the cartridge in, which released the C02 into the water, producing the desired seltzer.
Does anyone know if this is true or not?