I use filters that look like socks, don't know english name, LIKE THIS EXAMPLE
remember these filters have to remain always in the oil, so when not in use just leave 2 cm of oil in the bottom of the can and drop the filter till is is 99% collapsed into oil
that's something I've seen both in the "Petales" network and the "Oliomobile" site : there are waxes in the filtered part and these waxes dry between sessions, so the filter is clogged faster, keeping it in the oil prevents the waxes drying and the filter lasts much longer (they say it's a ratio of 1 to 10 in the filtered volume before the filter is blocked)
were do you get the filters from, as i am thinking of doin my own bio