What is the word on this? Palatal expanders widen the palate by slowly applying force between the teeth on the roof of the mouth. Couldn't the same force then be done without the cost burden if one could get the expander and to this themselves? Or with your own hands even?
I'm interested in this as well, as I have an asymmetry which would be much easier to correct with the precision that a finger would allow for. But how long can you realistically spend with your fingers in your mouth per day?
The bones respond to light and constant pressure, not pressure all at once.
Use your tongue and be patient. Plus how many of you know exactly where to place your fingers?
You say precision but that's assuming you know exactly where your finger should be placed. And do it for what? 2 hours a day straight? If teeth can revert after YEARS of braces, what makes you think your fingers will apply the right pressure in the right place enough to cause constant change over time?
Chew more. Suction tongue to the back of your palate. Eventually make your way to the incisive papilla. This thread is akin to saying you can straighten your teeth just by pushing on them with your fingers. Bones don't respond to heavy force from desperation. They respond to grams of force over years.