Confused with Fast Healing? FH = no K.O.?

[questionmark]

When atempting to knock out a pc with fast healing, if the subdual damage delt to the pc cannot knock the pc out does all the subdual dmg get removed by the fast healing? So is the only way to knock out a PC with fast healing is to drop them below zero in one round. Does fast healing work when the pc is unconsious(i.e. wake him up)?

What other interesting things have your pc's applied Fast healing to.

 

[CRGreathouse]

FAST HEALING
A creature with fast healing has the extraordinary ability to regain hit points at an exceptional rate. Except for what is noted here, fast healing is like natural healing.
At the beginning of each of the creature’s turns, it heals a certain number of hit points (defined in its description).
Unlike regeneration, fast healing does not allow a creature to regrow or reattach lost body parts.
A creature that has taken both nonlethal and lethal damage heals the nonlethal damage first.

It works as long as the creature lives, and it heals nonlethal damage -- not all at once, though, just preferentially.