I've got Magnus Snuffer glue ons and screw ins both, and only 1 Woodsman.....I wish now that I had all Woodsman BH's.
I get mine hair ripping sharp with just a file, but I first hit them lightly on a belt sander with it running. Paying close attention to keep the blades flat, I give it a quick touch on all 3 sides, then repeat once all the way around, and the rest is all file. Using a small 6-8" bastard file with a fine cutting surface I go about 10 strokes per side, then start counting down until I get to 2 strokes per side....and lighten up the pressure. I like a bit of a burr edge and find that it cuts very well just like it is.
I actually do more harm with a stone or strop than if I just leave them file sharp, which is plenty sharp to shave hair.
I've got some Grizzly 2-blade BH's I'll trade ya for those Woodsman if you want...send me a PM.