The highest ive heard of is 24 mg salt nic. I worked with a guy who was switching from cigarettes. He smoked for 30 years, and he had the same problem. Still reaching for a pack of smokes. The biggest challenge is going to be weening off the nicotine intake. I won't lie, it will take a lot of work and determination and willpower to ditch the cigs. But you have to keep at it. He found the best way to switch successfully was to go back and forth throughout the while over time slowly decreasing the number of cigarettes. In 2 years he went from smoking 3 packs a day to hitting the vape at 3mg of nicotine. As soon as he's done with his last 3mg bottle he's moving to 0 nic. From there it's an oral fixation that can easily be shaken.