You must have missed a step at some point. The oil should not be hard to push through the filter, but if you do push too hard, the filter can break and let some trash through. I never use the coffee filter and after letting the stuff settle out I've been able to push as much as 50-60ml through a single filter. As far as loosing your fina in the filter, if you don't purge it the most you would loose would be about 1ml.

Tell us exactly what you did, as I'm sure you missed something.

-moto