badflash, I forgot to even consider... but, what temperature do you think the mixture you make after adding acid will get to? Will it bake in the sun and maybe get near 100 C/212 F? If so, you really want to consider hydrochloric acid because your chlorine will really just be gone and in no time once it hits those temps (it's instant not counting the time the bubbles take to hit the surface).

Here, I'm posting a graph of what I am talking about:



Lastly, I would always send any new substance I am using/selling as a fertilizer to my local extension's soil lab. It usually only costs a few bucks, and you can always have them check for the sodium, chlorine, or anything else you might suspect may not have behaved as theorized given the complex mixture of other organic and inorganic compounds.