I've used the water trick too. It works great.
Dave, if you are looking to primarily drive ground rods, have you considered that fence post tool that is in the fencing material isle at Home Depot? It is a hollow cylinder with handels on both sides and a big weight at the top. Slide it up and down to drive it in. I haven't used one for that, I have a Bosch that I drive the last 2' after the water thing gets too tight. But I either saw someone else using it for that or maybe a home improvemnt show and thought, "hey, good idea"
My Bosch is either:
11219 EVS
11233 EVS
11220 EVS
11232 EVS
I don't know which one, I'm going off the manual here in the office.
Then get 1-3/8 X 18" spline drive. Extra length has been useful many times. takes the hub on 3/4 LB and will take a 1" HW. The smaller pipes get a little more silicone.
Then a chisel (longer is better), GR driver (after the second one cracked I just balance it on top. The guide cone cracks pretty easiliy, maybe user negligence letting the tool hang by it). And a 2-1/2 core bit.
