Careful grinding any jig heads........ lead dust floating around is not good. I suppose you could possibly do it if you were very careful about the location and wore a mask, but that dust will get everywhere.
Put them in vinegar they will be shiny as new. Rinse with water well them blow dry them . Warning brown or uncoated hook will rust over night rinsed or not .
If you want to avoid the possibility of lead dust contamination, melt the lead off the hooks and re-pour. Oxidized surface lead is generally soft or has been exposed to a corrosive atmosphere with moisture, salt, or acidic components. Adding 4% tin to soft lead and storing castings as airtight as possible will enable shiny castings to remain so indefinitely.