Here is a tablecloth I bought for 50 cents since it had a couple of stains.
This second stain has some rust on it as well as the stain. Some rust flecks may come out and others don't.
To treat the stains:
1. Place the stained part on top of a towel.
2. Spoon the juice of a lemon onto it. I squeeze mine right over the stain.
3. Cover the lemon juice with 1 teaspoon of salt. Gently rub it in. You can use your finger tip. I like to take the cut lemon and rub it in with that.
4. Let it sit for 45 minutes.
5. Rinse your linen with vinegar, (white is fine) followed by warm water.
6. Wash as usual.
This will work on items other than your linens. I just love to collect old linens and they all seem to have some sort of stain on them. Considering their age, it is not surprising. I use them even if they have stains. Most likely, they will get new ones anyway. lol!