Why would you use oil as the liquid though? Why not water? It's free, and has better heat capacitance.
It could be as easy as the fact that the units don't exist.
Ooh! That's a zinger right there. I'll be pretty open to paying via PayPal if that's an option, though. God knows when I was a seller using it, the buyers always got their way. Even if it's a scam, at worst I'll get my money back, which is all I really care about. If I do get a working product that's just a bonus.