From the manufacturers website:
SANITIZATION: No-rinse effective sanitization requires a solution of 100 ppm available chlorine. This will be achieved by dissolving the contents of an 0.8 ounce packet of C-Brite in 2 gallons of warm water. Thoroughly wet all surfaces to be sanitized. Let stand at least one minute. Drain and AIR DRY.
According to their instructions, you can mix the entire packet with 2 gallons of water, shake the hell out of your fermenter (or whatever it is you're trying to sanitize) and that should be sufficient.
FYI: That information came from the very first link that popped up when I went to google and typed in "c-brite."