Judging by the many vids and discussions on how useless/too much is being made, I have the opposite problem, I am not making enough of it. Is salt water electrolysis the only method of producing this compound? or am i missing something?

Yes, it's the only way to make it.

Most of the complaints of making too much were likely back when the only thing it was used for was to create Alumina. Partly to solve this problem, and changes to the chemical science pack in vanilla in the 0.17 era, I decided it would be a good idea to use it in the science pack, give a sink for the resource.

Although some people have complained that since I did that, now the is a shortage, the complaints are far less than the ones saying there was an excess.
At least this way around, you actually can just use the Hydrogen to generate power and vent the excess Chlorine.