Dip the tip of a cotton swab into petroleum jelly or wax, such as car wax. You only need a small amount.
Rub the cotton swab around the inside of the female, or open end, of the snap. This will coat and lubricate the inside.
Dip the cotton swab back into the petroleum jelly or wax.
Rub the cotton swab around the outside of the male end of the snap.
Add a drop of machine oil into the female end of the snap to further lubricate the snap. Repeat this process for any additional snaps.
Open and close the snap repeatedly. Over time, the snap will loosen up some, and it will be easier to open and close, even without additional lubrication.