I just used this on my endurapro key stems. I swear the resistance of the key on the downstroke is reduced atleast 5 grams. Its quite noticeable.
Amazon $7 bucks free shipping. Its a "dry" spray, not oily, not greasy, just teflon powder that sprays out and the alcohol that its in evaporates in a few seconds, leaving teflon powder. Super slick stuff. I applied it to the four corners of the bs stem (which are the corners that make contact on the slide downwards when you press the key). It super-slickened the downstroke. I applied it by spraying a lint-free cloth with it, then wiping the cloth while damp (it gets slightly damp for about 10 seconds) around the four corners of each stem on the key.
As ya'll know, I've done four 'mods' to my BS switches in the endurapro so far, to make them somewhat quieter and somewhat faster:
-First off I'm using unicomp which (I believe) is lower resistance to begin with than the original M, by about maybe 5gm.
-Second I've greased the springs with silicon grease to lower or "tune" the sound level to something more acceptable in my cramped apartment building.
-Third I've put rubber washers around the bucket receptable on the keyboard which dampens the bottoming "clack" of the key as well.
-And so fourth, I've now put the "dry teflon spray" shown above on the stems (the four corners of the square stem, which make contact on the slide downwards), which has noticeably reduced resistance.
So these BS switches are now somewhat quieter (they sound "thocky" like the topres, tho slightly louder than torpres), and somewhat faster (almost as fast as cherry browns, I'd say, without the excessive lightness of touch).
They're still unmistakably BS switches, they're meaty, they click and you can feel the buckle on your finger tips as normal, and all the rest of the good stuff. They're just more civlized, and way faster, BS switches. Really enjoying them.