I change the oil in my 12 WR450F about every 10-14 hours and I clean the oil filter (stainless steel) every other oil change. Anyway, to clean the filter I have a small jar with mineral spirits I dunk it in and kind of gently shake it to get some fluid going through the filter (but not stir anything up that may have already settled to the bottom of the jar). After I do that a bit, I spray out the filter with simple green, then fill up a sink and dunk it, etc. with soapy water, then wash with running water. I then use compressor blow tip to dry it out (not high PSI).
Anyway, this last time I noticed some residue at the bottom of the jar that looked a little weird. I ran one of those retracting pen magnets along the bottom and got some metal particles (about 2x the amount of a pencil eraser). The particles were very fine and this same solvent has been used at about 5-10 times, so I doubt I have much to worry about. Anyway, what are your ideas on where these particles are coming from? Clutch parts (stock), gears, cams? I have like 300+ hours on it.