I don't disagree. But when it started crossing streams (paths towards correction). I felt like it was best to step out since you and I agree on his possible corrective actions. Rather than stir up the same info, let it come from one source.No... LOL. We are letting a new reefer that there is more than just one solution to an issue. All will work an be effective. They can chose the option that works for them the best.
I personally have a big thing of Costco sea salt in the cabinet so that's where my mind went. If I didn't I would run it like @Reef. suggested then the next day add more salt water and let it evaporate to the correct salinity like you suggest.
We all want him/her to succeed! Not get confused and say "F this hobby".