Yup, we feel your pain. Best thing to do is leave the spots to the professionals. Many people damage fabric and set the stains by rubbing or applying the wrong home remedies to items with stains.
If you can, resist the temptation to play chemist! It is all chemistry, and pretty complex at that. Some fabrics have touchy dyes or weaves that make them easy to destroy if you don’t know what you are doing.
Depending on the type of stain and the fabric content, you could easily ruin a costly item. So hands off, Marie Curie, please leave the textile chemistry to us.