Hi, Carol. The white sap/latex from my dischidia created a bit of a mess after I'd finished repotting it. Wouldn't have thought to use oil. I'll try some vegetable oil the next time. Thanks.
Melted butter or vegetable oil is good for removing resins, but may not work on latex, which is chemically very different (related to rubber). I'd suspect a strong detergent solution might be better for latex. The sooner one acts, the better - try to get ot off before it starts to polymerise into rubber, then it could be really difficult to remove.