Heat exchange idea for recirc mashes

DISCLAIMER: I have little experience with the more advanced brew systems.
However, I had seen a system or two where there was a small container built in with the recirculation system running through it, and think I understand the science behind the system in general. So I got to thinking while cleaning out a deep fryer today...oil is a much better conductor of heat than water is, and much easier to heat with an electric element...would it be effective to have a small container full of oil with a coil running through it and an electric heating element that could cycle on and off? I'm thinking of Alton Brown's poaching contraption where he "turns down" an electric skillet so that he can more precisely control the heat. What if you had a similar setup for the recirc "tun" using oil instead of water...

Since no oil can be used indefinitely, you will need to change the oil out once in a while, just as you do a deep fryer, or your car, etc. All oils, to the best of my knowledge, suffer heat degredation. That being said, I would not want the mess or the expense of changing out oil versus changing the water in the heat exchanger.

I don't know if that's totally true. Do heaters that use oil like these need to have it replaced?

Warm Fusion Oil Filled Heater : Target

If you made it with a closed system, then you wouldn't have contamination issues.

TerapinChef said:

oil is a much better conductor of heat than water is,

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Not true, according to this site (Table 1):
Heat Transfer and Cooking - Kitchen Notes - Cooking For Engineers
Water has three times the thermal conductivity and over twice the heat capacity of oil. Of course, that probably doesn't account for convection currents and I'm not sure how that compares between the two fluids, so it may be a different story.

TerapinChef said:

and much easier to heat with an electric element...

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How so? I don't think that sticking a hot water heater element into a container of water is terribly difficult, nor do I see how you would do it any different if you were using oil...

Water does a perfectly fine job in a heat exchanger if you keep it moving - a little motor for stirring can do that job.

You could say oil is a better choice for a heat exchange over 212*.