That links extortionate pricewise i paid £32 for
10lts Hydrochloric acid 33%
25ltr drum of distilled water
25lrs Sulphuric acid 33%
Unfortunately the place where got it from dont want me to broadcast.

Until last 8 years or so there was only three internet sites providing info how to, none worked.
For me sulphuric at 19% running 14.2v. The only success was if wedged in aluminium in to a hole really tight.