I'm a fan of centrifuges but there is a definate investment economy of scale there. Centrifuge plus the pump and enough solvent stock to make it worth while.
60 GPH Centrifuge for WVO Motor Oil and Biodiesel | eBay
Faster and less energy usage than distillation but distillation separates the oil. Use both of them and you could actually reuse a tiny bit of your chain oil,
Oh! almost forgot, Biodiesel is a hell of a strong solvent. (Eats up most gaskets and all sorts of other stuff, fuel systems need special teflon seals to handle it.)