There are a couple of ways of doing this.
- Talcum powder will absorb the oil so cover the oil stain with talc. Press it in gently and leave it for about 20 minutes. Shake the talcum powder off (don’t rub it hard). Repeat if necessary.
- Soak the boot in lukewarm water with 2-3 drops of dishwashing liquid. Rub very gently with your hands then rinse thoroughly. Fill the boot with scrunched up old newspapers so they keep their shape and allow to dry naturally over a few days. Might be best to do both boots so if there is any colour change after the washing both boots will still look the same.