Your "
HYDRO" is hydro
chloric acid ...used for cleaning bricks etc. (MUCH less dangerous. Available in strengths up to 37% and useful for dissolving limestone & ironstone, in a glass with care. It is NOT Hydro
FLUORIC acid. (This dissolves bricks, glass & quartz.)
You cannot buy HYDROFLUORIC acid (neat) easily now because of its danger. It's a DECLARED POISON ......... one of the worst.
I agree with Doug, Crazy Pete is a mad dog (rants about 5000, racial intolerance & bias and now makes this stupid suggestion!)
DON'T "give it a go" with this "HYDRO".
There are NO SECOND CHANCES! edits: for typos & clarity