Hi Mark76,
Your magnet can lift 38 Kilograms? So, 38 Kilograms * 2.2 Pounds/Kilogram = 83.6 Pounds. That is one VERY strong magnet.
Most magnets (not all) have a dipole or dipole-like field, so their strength drops off extremely rapidly with distance. But with such a strong magnet, it’s still powerful enough to demagnetize your credit card from a fair distance, and induce voltages in nearby moving metal objects the same way that happens in a dynamo/electric-generator (like inducing voltages in your camera). And don’t let anything metal nearby accelerate into the magnet; at up to 80+ lbs of force, that could cause serious bruising of a finger, or the impact could shatter/chip the magnet (which is actually fairly brittle). And never never let two such magnets click together! You can separate them if you are very strong, but the impact will most likely chip one or both magnets and crush anything in between them.
One possible problem with magnets is only the metal swarf from the knife is magnetic. Most abrasives (SiC, AlO, Diamond, etc.) are not magnetic. So the small amount of abrasive released won’t be attracted to the magnet.
Maybe, a simpler solution is to use a fan or vacuum, to blow the swarf away from your sharpener. You could try a saw-dust collection scheme like those in a wood-shop (where air is used to suck sawdust into a collection bin/filter).
This picture is of a vacuum nozzle on a wood drill press. (It is not a coolant sprayer!)
http://www.leevalley.com/US/wood/page.aspx?p=58751&cat=1,42401,62604,58751

http://www.woodcraft.com/product/2001850/3121/multiple-machine-dust-collector-set.aspx

For me, I would hate to do this, because I find sharpening very relaxing and meditative. So having a loud vacuum running would just annoy me. Unless maybe the vacuum itself was far away in another room, and one ran a very long suction hose to the WEPS…
Instead, I like to keep a small amount of water on the stones, so that a swarf slurry drips off which I find easier to clean. Although, you don’t want that slurry to drip into your folding knife’s pivot, or the WEPS joints.
A much more complicated solution, is to use the opposite of electrostatic powder-paint coating. In powder-coating (for say for automotive and industrial), the paint particles are given an opposite electrostatic charge as the object to be painted. That way, they are attracted to and stick onto the surface for an even coat, and so that they can be permanently baked on in an oven. I suppose the opposite could work: Just hook up the WEPS and knife up to a Van Der Graff generator and give everything the same charge, so the swarf is all electrostatically repelled away. Just try to ignore sparks you will get from touching a metal door knob etc. And don’t bother to comb your hair, as it will all stand up anyways.
Of course, I’m totally joking! 
Sincerely,
–Lagrangian
“What grit sharpens the mind?” --Zen Sharpening Koan