Removing Cooking Oil From Clothing

I recently had a large area of Wesson oil on my brown slacks. I tried several things and finally I just soaked the entire pair of pants in Wesson oil. The next step I removed as much of it with paper towels. After that I used a half container of baby powder with corn starch all over the pants and let it set for 6-8 hours. I scraped all of that off that I could and then soaked the pants in a cup of undiluted Dawn. This sat over night. I tried to removed as much of everything possible. I hand washed the slacks and then I put them into the washing machine. Everything came out but I had a dream that I sat on a church pew and left a big oil mark. Don't give up. If you don't try you won't find out if you could have saved those pants.
Molly