Fuel soak will definitely gunk it up. I try and avoid it by using spitback guards on the 460s, foam on the 440s, and I always orient the filter the same way up so the top stays dry and easier to clean. The pleated filter has so much more surface area than a flat filter that if you keep the top 3/4 of it clean, it will still out flow a flat filter. The area with the spitback does not clean out easily, and if you double that area by flipping the filter upside down half the time, you will soon need a new filter.