My buddy and I have about 10,000 hours experience on WVO in several engines, longest running one has over 4,500 hours on it. We collect our oil from local restaurants and try to get it in cubies or metal pails. When I get mine home I pour it into an old bulk milk tank through a kitchen strainer, this gets the BCB's out (Burned Crispy Bits). The tank holds about 300 gallons, when it gets near to full I heat the oil up to about 160F. I open the bottom drain on the tank and allow any water to run out (not much if any when you can get good oil). After that I draw the oil off from the top through a 3/4hp pump and into a settling tank. Before it goes into that tank it is strained through a fleece blanket. I leave it in the settling tank for a day or two then transfer it (again, draw off the top) to my holding tanks (I have three, each holding about 250 gallons). I draw off from the holding tanks (yep, from the top) when I need to refill my fuel tanks in the engine room. I have three 20 gallon fuel tanks, two have WVO in them and the third has BioD for starting and stopping. I use two WVO tanks so I can fill the one that is not being used, so if there is any sediment left it can settle before the fuel is used. The only other filter I have is a 150 micron in-line in the fuel line leading to the engine. (I strip off all the stock fuel filters).
Neither of us have had any prblems using this system. We de-coke when the engines ask us to, usually around 2,000 hours.