Actually, it was David Etheredge who came up with the 3 points positive, 1 point negative. Prior to that all use of foot pads was either stand alone or 2 points positive, 2 points negative.
In determining the effectiveness, over 10000 users were surveyed as to their usage methods. Among those who responded, of those who used the 3 point positive, 1 point negative almost all showed a higher level of effectiveness than those who used the other 2 methods. This was in general across the board but the greatest difference noted was with those who had #1 systemic conditions, and #2 those with internal organ issues.
The use of zappers that did not have the ability to maintain a true square wave under load limited the improvement that was observed.