Here any post hole is an oh so slow nightmare. We use a pto on the back of a tractor driving a 12" auger. There's guaranteed big flints to knock the hole off course for a start. Doing our front fence I lost count of how many shear pins went on the auger.
Could do with one of those big heavy axe bladed, shovel type things for roots too.
A few weeks ago one of the other unit holders moved out, and dumped a load of stuff in his skip. I had a dig around as you do, and there was a plastic box full of water with some power tools. I dug this out:
thinking that at worst it might donate the mains flex as the one on my die grinder is breaking up around the end of the strain relief. I left it to dry out, and yesterday I tried it and it works just fine. I might take it to bits and clean it out before using it, but I just wish I'd grabbed some of the other bits, though I did get some plastic boxes for when I get time to sort things out, and some brand new bricks.
You wouldn't think I'm trying to clear some space out of my unit, would you?