RE: Daiko Compass Fluid Replacement
I believe all sorts of fluids have been used for filling compasses. You will find kerosene, mineral spirits, different alcohols (ethanol, even methanol, glycerol (aka glycerin), oils and who knows.
Best bet would be to sample a few drops out of the fill hole and taste.
One of my compasses is glycerin filled. I had to drag it home as carry-on baggage on a flight. To avoid it being confiscated (air bubble gave it away as being fluid filled), I drained about a gallon of glycerin out of the bowl. Glycerin is quite thick, more like oil compared to ethanol. For us northerners it should be noted that freezing temperature for glycerin is*0 F.