You don't use a random cutting solution, you use the same juice with no nicotine. A lot of juice makers offer 0 nic versions for people that want to just enjoy the act and flavor of vaping without the addiction, and for this specific purpose of cutting the nic level because they only offer certain increments (usually 3%, 6%, 12%), which may be too high for one's personal preference.

Just as a thought experiment, what you'd really wanna do is change the salt nic formulation, i.e. the acidic compound which is added to freebase nicotine to convert it to a salt. This directly shapes the pharmacokinetics of the resulting nicotinic effect from vaping it, which is what leads to the common knowledge that salt nic hits harder, but doesn't last as long as freebase. That isn't universally true at all, but is a result of the salt formulations that are popular in the market.

I worked with a scientist that once formulated a 20mg/mL solution for me that had similar throat hit to the 40mg/mL products I was using & had a very steep onset curve, and I found it to still be very satisfying even immediately after swapping. It wasn't a successful product though because for the consumer, 20mg = 20mg & 40mg = 40mg

Guess my point is that the novel ways of using tech to improve weaning off nicotine using vaping do legitimately exist, but they don't have a place in a free market so we won't have it while regulators stay luddites on the issue

For those like me who have never heard of (E)VAPI or Honey Cut and want to read a disturbing story of how illicit products may be made of pretty much anything, there's a read from Leafly