"I wish I knew how this stuff worked," Jon said. The stone glowed, granting his wish, and then he knew.
According to what the stone told him, one spray of the "lust potion" on himself gave him about a half of an hour of influence on any female close enough to smell the odor from the "potion" on him.
Any female from the age of thirteen and up that was affected during that half hour of time would forever have an uncontrollable urge to have sex with him. In their mind, they would find a way to justify it, even if it went against their morals.
If Jon wanted to affect females for more time, he'd have to spray himself with the "potion" more times. One spray equaled a half of an hour. So if he wanted to affect females for, say, two hours, he'd have to spray himself four times.