@mike, Last week I started using 7 of the 4" 10 micron socks sold by Marc at melevsreef. I figured that he would have a good sock for sale since he is a reseller now. These socks are well made and they hold up in a washing machine just fine. They also polish up the water well. With 7 sock chambers, I can use the 10 micron socks on a regular basis without an issue.
I've been changing them out every few days but they haven't all clogged up at the same time as of yet. The first three socks in the first chamber clog up after a few days but the 4 socks in the second chamber are still working fine by the time I change out the socks. They definitely clean up the water far better than the nylon socks that shipped with my dreambox.
The only problem with them is that the 4" plastic ring is slightly larger than the smaller metric RE sized sock openings in the dreambox so the socks don't seat properly but they do the job. The sock silencers help to seat them in place well enough. When RE starts selling felt socks, I'll get a set of them.
Here is a link in case you are interested.
http://melevsreef.com/catalog/4-filter-sock-10-micron
Good Luck!