If you use a galvanometer, you would have some luck. The concept of earth as a large electric sponge is a myth, especially now days with the utility neutral mentioned above, RF, etc..

Galvanometers can be made easily, hard to calibrate a home made though. I have one on my earth resistance meter, and it never fails to surprise me what comes from the ground...... OK, maybe the term is scares me.

I guess the answer is with a real sensitive meter, probably. BTW, rural is no protection, the worst I ever saw was in a VERY rural (I'll tell ya how rural, even Sparky66wv would think he was in the woods [Linked Image] )location with an earth return neutral..... dang near ruined my meter.