Metallic mercury is actually pretty hard to absorb. You could drink it and most of it would pass right through with relatively minimal uptake. (It used to be used as a treatment for syphilis.)
Mercury salts, on the other hand, are much easier to absorb and much more dangerous.
Going to take a break from high grade petshop to edit this and the new muraaki series. Highgrade petshop isn't particularly difficult to do, but all the speech boxes need a lot of formating and centering to fit and it's a huge pain.