There is a new product on the market. It's called Resolve Gold remover. It's by Dawn. I love it. I use it on my DH's jeans after he works on our vehicles. I bought a bottle of the Grandma's. It's pricey and to me it was useless. I used it according to directions and nothing but a pitb. Another product I used to use when I had to deal with well water was "IRON OUT". At the time I used it with the laundry detergent. If I needed to only use a small amount I mixed a teaspoon to 2 cups of water and used a Qtip to apply. So far I really like the Resolve Gold. If it's just on the edges, I would just do a section at a time. It only has to set 30 secs. I would pour a small amount 1/4 cup and just apply wit the tip and see what happens. You may want to try it on a sample scrap of your fabric for a color test. But it did no harm to my DHs jeans. I also tried it on greas and egg from breakfast one day. Worked. No harm to my green shirt. And what Car-in-only suggested. Since it works for her. I'm checking that out also.