In the US they generally add toxic chemicals back in for that kind of thing to prevent people doing that.
Where I am it's called "methylated spirits" and IIRC the boing point of the additive is very close to that of the alcohol so it's not possible to distill it out.
Hopefully the only country with a market for that.
With the 99% stuff, the laws of physics compells them to use the benzene.
Financial considerations also exert an influence on the process.