They work, I got some to fix some swing tops that had bad seals. I find it easier (read:cheaper) to add corn sugar to my bottling bucket. After measuring it and boiling it with some water, of course.
Kelpie Home Brewery, Lafayette Colorado
Primary: Creek Dog Stout x2, Two Dogs IPA, Grinning Kelpie Wheat
Secondary: empty :(
In Bottles: Belgian Wheat