Well the title lied. You have to buy $180 worth of chemicals...then once you use them...you come out with this!
Flip the 5er on its side, cut an 8" hole, drop your sock into it with whatever micron you want. Then you have dual action filtering. Sock catches most of it, then you have about 2" at the bottom where water pools and solids sink.
Literally thought of this last night and took me 5 minutes this morning. Threw it under our post expose rinse out station.