You can try washing with detergent, shower gel, shampoo and hand sanitizer! These are almost neutral detergents, which can be used to wash silk!
If the silk fabric itself turns yellow, you can soak the silk clothes in clean rice washing water and change the water once a day. After three days, the yellow will fade.
If there are yellow sweat stains, you can wash them off with wax gourd juice.
You can try all these tips!