I've posted an instructable on how to remove fragrance by heating. It's not the safest thing in the world, but it worked. http://www.instructables.com/id/RemovingReducing-Fragrance-in-Baby-Oil-Baby-Pow/

Why not water cooling, or get something like mineral oil, just an idea, since it's not an uncommon product. For removing the stuff PKM's ideas sound good, you could also distill the oil and seperate the fragrancing etc, the minerals would be left as sediment and the fragrances would distill off first, I think.

Ok, I just found this, so I concede that it can be done (the fan does still appear to be quite stressed however).
It was just that in my experience, mineral oils made such good insulation and with no evaporation taking place, tend to retain heat . But what do I know :-)

BTW: I am now (at least for now) unable to "listen" to the audio from these videos while I am at work (they took my speakers from me). So I am not really sure what they say on that video, but it looks like they reached their goal :-)

blech... i was gonna add to Tech-king and Godhart's discussion but the reply scrolls into oblivion. To answer the question in the reply: mineral oil may be as good as regular air as a heat transferance fluid. In order to get the same protection as water you'd need a larger heat sink. This is related to water's high specific heat, which would effectively allow the water to hold an equal amount of energy at a lower temperature (relative to the oil). You require a larger heat spreader in a system running off an oil because in order to maintain the same operating temperature the oil has to give off more energy (in the form of heat) which requires a greater surface area. That said, if you can afford to use a larger heat spreader (Like a car radiator instead of the 6 by 6 radiator on my commercial liquid cooling rig), both in terms of money and space, go for it. It'd be kinda interesting to use a computer as a space heater. Truthfully the only real constraint to using oil would be the overall system's stability in terms of it's temperature. I'm not certain that an oil cooled system could soke the heat generated by sudden heavy processor activity the way water can... but... still... this sounds interesting.

Baby oil is mineral oil with Vitamin E and fragrance added. Following up to what PKM said... that only works if the fragrance was distilled Via Fractional distillation and the fragrance still contains Ether compounds. It's not impossible but considering that it has to be 100% hypoallergenic, I don't see Johnson and Johnson using such a fragrance (ether being toxic). Hydrocracking (which is the technical name for what Killer suggested) could work, but as Tech king said, it's got it's own set of issues. Alternatively, you can probably filter this stuff through activated carbon with out too much of an issue, depending on the resevouir on this setup (I have a liquid cooled computer.) a fluidized bed would be fairly easy to rigup. The main thing you'd have to worry about with this idea is carbon granules getting down into your oil pump, and the eventual removal of the carbon after the fragrance is gone. (I think Vitamin E degrades in light, but I'll have to check on that.) That all said... Mineral Oil is very bad as a medium for heat transference. If you're worried about leakage I suggest just running a water setup without closing the system (which puts it under pressure as the heat rises). This is easily accomplished by taking the lid off the resevoiur. I get a bit of extra evaporation, but it's not too excessive. I top off once every few days. I can't say more without actually seeing the system you're talking about though...

You could try water washing (add water, shake a lot, wait to settle, decant water with hopefully dissolved fragrance etc). but you would need to be very careful to remove all the water- maybe salt out the oil after water washing. A similar technique with some sort of alcohol (eg isoprop, whatever the systematic name for that is) might work better to remove the fragrance but I'm taking a stab in the dark here so don't quote me on that. However, if the fragrance and vitamins don't interfere with the computer working I'd be tempted to leave it alone and just seal the thing well- you'll have a slightly nice smelling computer, anyway.