Try packing the handles in cat litter (clay). Use the cheapest you can find. It's the same stuff they sell as oil absorbent at the auto parts store. Keep them buried in it for a few days.
It will pull oil out of a concrete floor too. Since the metal in the handles may rust I don't advise wetting the cat litter, but when pulling oil off of a concrete floor, spread a 1" layer covering the spot and mist it wet. The next day most of the oil will be in the cat litter. Scrape the thick stuff off first. Repeat if needed.