yep I had not heard of it untill recently either scott, I then stumbled across this...........
As an insect destroyer the juice of the potato plant is said to be of great value; the leaves and stems are well boiled in water, and when the liquid is cold it is sprinkled over plants attacked with insects, when it at once destroys caterpillars, black and green flies, gnats, and other enemies to vegetables, and in no way impairs the growth of the plants. A peculiar odor remains, and prevents insects from coming again for a long time.
The Farm and Household Cyclopedia - circa 1888
...... Not had a chance to test it out yet as all my potato plants came up back in september. Will give it a go next year though. Worth I try I guess.