Google 'muriatic acid'... it's another name for hydrochloric acid. Plus if it's taking off chrome, the solution will then contain dissolved chrome and that's nasty too.
Seriously, don't make the mistake of thinking brick cleaner isn't 'anything that strong' - with battery acid (sulphuric acid) and caustic soda (sodium hydroxide) its one of the three most nasty readily available chemicals on the shelves.
Please be careful, it really is nasty.