I’ve been using a biofeedback device lately which requires an electrolyte solution to be applied to help the parts that attach to my skin to make contact. I’m running low on the solution, and it’s not so much that the replacement stuff is ridiculously overpriced, but it seems like a pain in the ass to have to go through all the steps of ordering it by mail.
I’m convinced that there’s something in my local pharmacy or even supermarket that will work just as well. But I’ve asked a few pharmacists and tried a couple of search engines with no luck so far.
Basically the products contain some variety of salt. Not necessarally table salt.
It the biofeedback is for a required/sanctioned treatment I’d stick with the authorized gel or solution. The particular gel/solution may have some specific required properties.
When I was in school, one of my design projects was a biofeedback device. We got a recipe for an electrolyte solution from an electrode vendor. It was basically a salt water solution with a tiny bit of liquid soap in it (our electrodes were to go in the hair, so it was useful to have a detergent to try to remove some of the scalp oils). I’ll see if I can find a link to it.
Man, it’s amazing how long stuff can stay on the internet. I found an old version of the project website (though after I was involved). It looks like anything greater than a 5% NaCl (table salt) solution doesn’t significantly reduce resistance. Adding a little bit of liquid soap does help, but I don’t have an exact amount as to how much was used.