Maybe you need to give the soaking longer to work. I once had a waitress spill a large quantity of greasy, tomato-bassed buffalo chicken sauce on my lap and down my leg, all over a new pair of light kahki-colored pants. I soaked in Oxy Clean for several hours and it didn't help. I nearly pitched them out but decided I had nothing to lose be trying again. I soaked them for 3 days, changing the water and rubbing the stain every day. The stain disappeared and I had my pants back.