there's only waterbased / water soluble coolant .. no oil based
so far, Feser One is dielectric coolant ... google to check it's testing on a running fan
but there's a trick .. it lowers the electrical conductivity .. but not negates them .. but somehow a few drops will cause electrical failure .. depending on their volatage tolerance
distilled water is the best .. just use those hose tighteners to tighten them and you wont risk any of your electrical failure .. it just cost RM0.50 each .. from your local hardware shop
the link you provide is either use mineral oil (baby oil) or silicone oil
both of them pawned by a cheap distilled water .. sorry dude, distilled water is the cheapest, most reliable heat transfer medium you could find .. there's no other fluid/liquid which can comes with that price ... not even mercury
i cant find other better prices

you could get La Boost distilled water for RM5.50 for 5 litres at 7-Eleven ... you may get cheaper other places ... i cant find any at Tesco

however if you need a REALLY good fluid transfer .... this product it's not available in malaysia atm ... its
Nano fluid (not FluidXP) is the best so far .. it's not coolant and non-toxic .. if you dont mind it's milky color