Tool is a frequency generator that wakes up the reed valve inside the tire pressure sensor. Older styles, such as used on C5 vettes, did use a magnet to wake up then sensor, and any large magnet would work.
Dealers are given the special tool.
Just remember, if you rotate the tires, and do not rotate the spare to the ground, you do NOT have to reset the TPM system. It is only looking for four identified sensors, and those are already on the ground..
As for politicians, I would love to have Ted Kennedy come out and check my tire pressures.
However, I will not allow him to drive the vehicle if we are going over a bridge.