...day I wore them DUH? How can I get it out? Vanish, washing up liquid and Fairy non-bio haven't worked (they are dry clean only but have survived so far on a cold gentle wash)
I'd just take them to the dry cleaners. They're masters at getting out stains. Personally, I wouldn't have washed them at all. If you exposed them to any sort of heat (like warm water) you may have set the oil stain.