I have been using coffee/tea filters for filtering first then going to whatman round ones for the fine filtering with a Buckner funnel. I had been having issue with stuff getting under them so I recently tried the "charmin plug" using using a funnel & fiberglass. I took a wide mouth funnel and stuffed fiberglass into it.
This thing was fantastic, very fast filtering and very clean solution. I'm not going back to the other way.
A lot cheaper to run.
I also now do a pre-filter to skip the coffee filter. I stuff the funnel with a large piece of fiberglass and then put another small piece of fiberglass at the top (the pre-filter).
I just remove the "pre-filter" to get rid of the large crap and for the next filtering I add another pre-filter.