Some years ago I had a plowdisc that I weld the holes to creat a surface for barbecue. I don’t know if is the case on your kind of material and finishing but it was stained and rusted. I forgot it in the rain and it stood full of water for few days. When I lift it to dry the dark rust become dislog with water and them when I lay my hands on surface the rust was all gone.
As I said before, I don’t know if it work with stonewashed and etching blades but if you have time put it inside a box and cover with water for few days the rust will gone, but I don’t know if the finish will gone too.
