I am in agreement with oiling the Rotary Cutter blades. Why? When I sliced 2 fingers trying to remove the blade from the cutter, I found that spraying WD40 on it make it loosen and come off easily. (thanks to someone who sent me that tip.) Now, when I notice a lot of lint and gunk on my blade, I take the assembly apart and wipe the blade to remover the lint that seens to collect at the post. This also inhibits the movement of the blade. Spray that blade and keep it rolling.
No more cut fingers from struggling to get that blade off the post. And while we are talking about blades, here is a good place to stock up on new ones.
http://www.houseofhanson.com/lpsharp.html
Having 10 blades on hand is a real Treat...or should I say, Luxury
And why would you throw those blades away? They can be recycled just like a lot of other things. See above link.