My dippy daughter washed her boyfriend's oily mechanics uniform with a load of my grandsons clothing, and now the whole lot, not surpisingly, stinks of oil.
She's admitted defeat and passed them all to me (oh gee ta!). I've pre washed the lot, on a 90 degree wash, twice, but they still stink.
There in the dryer at the moment, i somehow thought the smell would lessen some whilst in there (don't try to understand my logic!) but oddly enough, it hasn't, lol.
So they'e going back in the washer again very soon.
Just an idea but after this wash load is finished let the machine fill up and add a couple cups of bleach or Clorox and let it run a bit to get rid of any oil reside that might be lingering.