[Funny]

Cellulose doesn't "like" gasoline like Cellulose likes water. The fibers that make up the paper are what absorb the water, the gasoline fills the pores in the paper. In other words, the voids in between the fibers hold the gasoline in the paper. Water, on the other hand, gets absorbed into the actual cells of the fiber. This is called plasticizing cellulose. I hope that helps.
And you could always use the vacuum to draw the gasoline upward through the filter, and have the water fall back down with gravity. Just a thought.