It's not a donation. You are literally giving them money to dig a hole.

No, the money is paying for the cost of operating excavators. This is not a charity, the CAH team is not going out with shovels, the men driving the excavators are not volunteers. You're paying them to dig a hole. When CAH runs out of money for hourly expenses of hole-digging, the digging stops. That's it.

You pay for N seconds of digging. That's the whole thing.

Yes. You choose the charity yourself, send the money to it directly, and, most importantly, you leave the CAH completely out of it, because they don't care.