When you hold the X button, at the bottom of the screen it will say 'Hold X For a Hint'. If you continue to hold X, you will use a hint. If you just press the button for a second it will not count, as you need to hold it for longer, more like 3-4 seconds. This achievement will unlock along with A True Pirate, Monkey Master, Speed Demon, and Turning the Lights Out, if those requirements are also met, at the end of the game.
Use this as a guide if you need help but don't want to use hints.http://www.worldofmi.com/gamehelp/walk/monkey2.php