dragoon, what you have described (icy cold water squirted in the ear) is a good test for brainstem function. Also known as the caloric test, it's also used as one of the tests for brain death.

I once watched some doctors in the Intensive Care Unit do this test on a patient who seemed dead - no pupillary response to light, doll's eyes, no response to noise and painful stimuli (nipple pinch - ouch!), no response to intravenous atropine (the heart rate should increase). Someone got a cup of cold water, the consultant dipped his finger in and said "that's not cold enough. empty that cup, fill it to the brim with ice and then put some water in." - sure enough, there was no response to the icy cold water either and the patient was disconnected from the respirator and left to die.

So ... the water should be ICY cold. The way to do this is to fill a large cup with ice cubes and pour water over it, stirring to form a icy cold mixture (aka a freezing mixture). DO NOT DO THIS FOR FUN. It is a horribly unpleasant feeling to get icy cold water squirted into your ear.