He said the old name for it was Stinkwater. But if you have any Aquafortis he made, just cut it in 3 with water & same thing.
Now this is something I found out & sounds crazy but it worked for me.
You have a banana trees in your yard ? If ya do, pull one up & cut it at the base & let the juice run into a bucket. That stuff will blue a barrel Instantly & I mean Right now. Or it will in AL on this mountain anyway. Don't know what is in that sap or juice, but it will dang sure turn a new saw blade blue/black. I cut my trees off at the base every year & every single time, the saw turns black. Every year I say I am going to save some & see if it will keep, but by the time I cut all the trees & elephant ears getting ready for winter, the ol man is done in & will gladly buy a bottle of stinkwater rather than try retrieve some.
But just for fun, you guys with some banana trees, try it. Take a saw or machete & whack one off & rub that juice on a piece of clean steel & watch it. Maybe it is the soil here has a mineral in it ? I don't know. But it will black/blue a piece of steel lickety split.

It may brown a barrel too, never tried it.