When I do temperature measurements so set cut off etc..I place the temp probe on the FRONT of the LED. This shows just how much heat is also radiated from the front of the LED and so why I think it would benefit from cooling in CONJUCTION with a standard finned case.
No, the temperature probe gets hot because the visible light from the LED is converted to heat when the temperature probe absorbs it, not because the LED is emitting heat out the front. LEDs emit nothing in the infrared. What comes out the front is visible light, and remains visible light unless absorbed by an object and converted to heat. By putting oil or anything else in front of an LED you're actually absorbing some of that visible light, and converting it to heat. This isn't helping to cool the LED one bit. All it's doing is decreasing the visible output.
In short, it's great you're thinking outside the box, but in fact if this idea had any merit the LED industry would have been all over it years ago. Same thing with using peltiers to cool LEDs. Every few months we get another thread on that. Now I just copy and paste my answers from the last thread into the present one.
The Hydralux bulb uses oil for a different reason-namely as a conduction medium between an internal heatsink and the outer surface of the bulb. Still a pointless idea as the flat bulb has less surface area to ultimately dissipate the heat than a traditional finned heat sink. The claimed "benefit" is that the oil spreads the light out past 180°. I personally don't see how this is a benefit as a light source with a spread of 180° or
less is ideal, provided it's mounted face down on a ceiling. Any light past 180° ends up being partially or entirely wasted inside the fixture. So even here it isn't really a great idea. Not to mention that the Hydralux bulb lacks one of the major benefits of LED lighting-namely durability.