Chiburi is translated literally from
Japanese as chi (
blood) buri (flick). It is the process by which one removes blood from their
katana. In
Iaido, this is done before placing the blade back into the scabbard (known as
noto).
The traditional chiburi position is holding the
katana with the right hand,
hilt close to the hip, with the tip of the
blade pointing downwards and to the left. Most likely in
samurai movies and
samurai anime you have seen it done as a slash at the empty air, where the
blood flies off in a perfect
arc. The
iaido version is completely ceremonial.
Blood is very hard to get off a
katana, even a real chiburi swing usually won't get it off. Most likely if you have blood on your blade, you're going to need to wipe it off. And yes, it is important that you get the blood off before sheathing the blade. The
chemicals in blood will not only damage the polish but may eventually start eating away at the metal, which will damage the edge of your
weapon.
Not that I know from
personal experience or anything like that. Err. Heh.