One of my rear abs sensors is not working properly and needs to be replaced. A new one is close to $300. I found a good deal on a used set from a sc parts dealer but from the pic they look like they have a bit of surface rust perhaps. Is there a good way to clean these up or should i just throw them in as is. Here is the pic he sent me:

 

I would clean up the outside of the bore. I have had them stick and difficult to remove from corrosion. Clean the tip to make sure metal dust/flakes doesn’t affect the signal. Other than that throw it in and roll. They rarely go bad unless damaged from a bad wheel bearing. You should be good with the used unit.