Bob, using these is NOT the same as bottles. More like using actual full kegs for carbonating. Since they hold 1.3 gallons you prime them like they hold ONE gallon. So about 25% LESS sugar is used. Using one of the online carbonation sites makes it easy.
Also, if you go over the previously stated CO2 volumes limit on these (far less than glass bottles or other kegs) you increase the potential for keg bombs rapidly. The threshold is far lower than beer bottles.
It really sounds like you've never used these before so do everyone a favor and stfu about it. I HAVE used them before and did look up the info I'm posting (from both resellers and from the manufacturer's of them). While I wouldn't use 1/3 of the sugar for the volume of beer I would keep the parameters in mind. Otherwise have a mop on hand or put these in a plastic bin while carbonating (to make cleanup easier when they pop).