If I remember rightly, there is a cvar you can set to make the wall crawling a toggle rather than having to hold down Ctrl. It might help not having to keep it pressed down all the time.
That is correct. If its the same in Single Player as it is in Multiplayer, people should open up the 'chat' (default key 't'), delete the command 'SAY' and replace it with 'CROUCHMODE 1'. Now every time someone crouches, it will be toggled on or off rather than needing to be held. Changing back to 'CROUCHMODE 0' restores it back to it's original functionality.