Beacon of Truth and Light, did you even read the request? He asked for
cheap liquids above 3 gm/cc, and you give him a 2.9 gm/cc liquid that
"The price for small quantities (1 to 4 litres) of LST Heavy Liquid
S.G. 2.85 is $670 US per litre + freight"
2.9 g/mL? Pffft. That's not heavy. What do you want this safe liquid
for? Grind some cheap, heavy, "safe" electrium (nickel, copper, zinc,
brass, bronze, silver, indium, tin, or bismuth) into dust: The smallest
and smoothest like brass will flow the most like water. Soot does.