I've noticed when using my WFT to trim my brass mouth to overall length (I measure case base to mouth though the WFT indexes off the case shoulder) that from case-to-case I get caliper readings varying from my target value by .002 to .004", sometimes more. When I see these variances I put the case back in the WFT repeatedly until the overall length is at or within .001" of my overall length target value, which it does. Trying to figure out why I was seeing these variances, I started looking inside the WFT at the WFT shoulder and found small particles of brass had landed on the shoulder from the cutting tool. I use a Q-tip to clean off the WFT shoulder when these variances occur but think there might be a better way using some sort of simple tool or hand-made tool to clean the WFT shoulder prior to trimming each case, which might avoid repetitive trims. Any thoughts about a fast and simple way/tool to keep the WFT shoulder clean?