[Amps] Can distilled water be used for a dummy load ??

[Jim Thomson]

My  hb 50 ohm dummy load  consists of  4 x 200 ohm globars in parallel  [type SP, glass bodied
and suitable for oil immersion].   Each resistor is 1" diam x 12"  long. [275 W CCS in air]
 Each resistor  resides inside it's own  2.875" OD x sched 40  Aluminum tube. 
 All 4 x thick walled  AL tubes are heliarc welded. 

I heard some place that instead of xfmr oil, that  distilled water can be used instead? 
The same glass bodied type SP  resistors, [50 ohm, high wattage]  are used in  water cooled loads,
the type that  has the garden hose on one end, etc. 

Seems to me that distilled water will conduct heat a lot better than xfmr oil.  The question is,
will the use of distilled water in a 7 gallon metal container, with resistors immersed present any
swr problems ?    If I remember correctly, swr was high on heath cantenna loads  if no oil used at all,
and dropped to dead flat once the oil was poured in.   There was also a similar 50 ohm load in the
old arrl books, same resistor as I'm using but it was a single 50 ohm unit, and not 4 x 200 ohms in parallel. 

I would prefer not to use xfmr oil if at all possible.   It's a little tougher to get a hold of these days..and not cheap.
My main concern however is something leaks. Water on the concrete floor in the shop is one thing, but 7 x 
gals of xfmr oil is a disaster.  Can you add  rust inhibitor's  or  glycol to the distilled water ?? 
Do I even  have to use distilled water, or will  clean tap water work ? 

A 50/50  mix of water/glycol will result in a 265 deg F  boiling point..BUT the heat transfer is no
where as good.   I'm using a new 7 x gal paint can for this project, the 4 x resistors and the welded AL
tube assy, hang from the top lid. 

Thanks... Jim   VE7RF