Electrolysis with a Schnee Bath in Woodhall Spa??

We went to Woodhall Spa in Lincolnshire to look for a bird on the River Witham. I was intrigued by the history. Woodhall Spa's prosperity was based on a failed coal mine that released mineral waters. But it was the Schnee Bath that really got me thinking. As far as I can tell from a little poking around on the Internet, each limb was placed in a porcelain dish which was filled with warm spa water. It appears that the electric current was passed through the mineral water and not directly through the body, but I can't be sure of this. So they would be performing electrolysis on dissolved aqueous salt solutions. Again, it is not specified which metals had bromide and iodide salts but would be likely to be potassium or sodium. So say we had the following ions in solution: K+, Na+, Br-, I- and from the water H+ and OH-. Halide ions would be attracted to the anode so you might well get bromine gas! K+ and Na+ are more reactive than hydrogen so you'd get hydrogen at the cathode. Sounds dangerous but it clearly wasn't instantly fatal. Anyway, we did find the White-billed Diver: