I have large brown stains on my white cotton gloves that are hand wash only. I believe the stains are from my moisturizer combining with dirt when wearing the gloves both indoors and out, running errands (i.e. from touching stair rails, items in stores, etc.).
First check to make sure your gloves can be safely washed with bleach – you should never bleach wool, silk, mohair, leather, or spandex. This is especially important since some cotton gloves can be blended with spandex. You are correct in your assumption that the stains are being caused by your moisturizer. It sounds like a small amount is transferring from your hands to the gloves and building up overtime. It has an oily component, which will help attract dirt from the various surfaces you touch, and make stains much more difficult to remove.
If your gloves can be safely bleached, I recommend fully submerging them in 1/4 cup Clorox® Regular Bleach2 per gallon of water for 5 minutes. Drain the soaking solution and then wash in warm water with detergent + 3/4 cup Clorox® Regular Bleach2. Air dry and check for success.
If your gloves can’t be bleached you can pre-soak the gloves before hand washing them: add a capful of Clorox2® Stain Remover and Color Booster to 2 gallons of water and fully submerge the gloves for an hour, then wash. Again, this assumes the gloves can be safely washed.
Does anyone else have stains on their gloves that they are trying to remove?