hello i use devining rods all the time to find water mains in the street.....some people look at me like i have 3 or 4 heads..........i use 2 brass brazing rods with the flux removed........they are 36 " long..........i bend the first 5 or 6 inches to a 90 degree angle to use as handles..............then hold them together and when you pass over a pipe........you can not keep them from sprreading out.............. but i must admit ......i never tried to discern which pumpkin seed will do well............ i didnt beleive they work until i tried it for my self...............wheni saw this guy do it the first time.....i thought he was crazy......but when you cross water...........or even a drain pipe in the street...........YOU CAN NOT hold them from moving........now i use them all the time.....and have better accuracy than expensive electronic meters designed to do the same thing................. thanx for listenin..........bruce