I've just about tried everything out there but in the end it just takes a little elbow grease and an electric drill with a good selection of buffing wheels.
Here's my boy helping out with the hubs.
I am with you Raywood, I ordered a bunch from Vickie and it sure makes it easier. For water stains Mr Clean works well but is a pain - you can buy a filter and water softener that attaches to your outside facet and is good for months.
Careful watering the dog until you seal all the wires.
I had a permanent black magic marker on a leather seat once. Rubbed that thing on it and it removed it, BUT it faded the leather in that area slightly. Looked better than the magic marker though!