I did something similar but without the gum stage. Since I was buying concentrated nicotine liquid and diluting it with a PG/VG mix, I would just reduce the strength until I was literally putting a single drop of the strong nicotine liquid into my 10ml vial of PG/VG. Then to prevent just vaping more I would count the number of puffs per hour and reduce it until after one puff per hour I'd go to one puff every 2 hours etc.

I drew it out over several months. The thing I was really surprised by was that when I finally stopped, I still felt withdrawal symptoms, which is a testament to how addictive nicotine is, given what a tiny amount I had reached.

I actually tried something similar, but failed. I'm curious, how often did you dilute and by how much?

This was my setup: I mixed up 100ml of e-juice in a graduated bottle at whatever strength I was using at the time, somewhere between 15 and 20 mg/ml, can't remember exactly. From that bottle, I would fill a separate 10ml bottle, which I'd use to refill my tank. After refilling the 10ml bottle, I would top up the big bottle with VG/PG back up to 100ml, so diluting by 10%. I was vaping about half a 5ml tank per day at this point, so the 10ml one lasted about 4 days, and I'd top up the tank every morning. The theory being that the stuff in the tank would also get somewhat diluted every time I topped it up, since it would gradually get more of the stuff from the most recent filling of the 10ml bottle.

But somehow I just ended up unconsciously vaping more and with longer puff until I was at one tank per day, and then more than one tank per day.