It's been mentioned before, but I second 0000 steel wool to buff it, then I wife it clean with a damp cloth, then dry it then oil it. (I favour almond oil or coconut oil.)

As for sticking it in the ground, that's something that always makes me shudder.
In all the historical re-enactment groups I have worked with we were band from doing that because the swords had to stay away from anything that might corrode the blade and make it dangerous.

If you must do that, heavily wax the blade with the sort of stuff you would use to wax a car.
Once you've done that go ahead and make the hole for the sword with something else. Get a really long bit of metal just for the purpose. Dig it in deep, pull it out and gently ease the blade into the hole that's left. That way you will lessen any chance of it being scratched by little stones in the soil.


Good luck with it all.