I use an old 1 liter vitamin water bottle. I add 3-4 Tbls of BS, mix it up well, and add my oils. Pour it on and then wait 10 minutes to rinse. Sometimes I add sea salt, sometimes not. But if you do, only make it about 3.5% of the total volume. sea water is 3.5% salt. So you want it to be as close to sea water as you can get it. Then I use the same bottle and mix about 3 Tbls of ACV with the water. add my oils again, and pour it on. My locks are 6 years old and fully mature, so I can leave it on a few minutes. Bu for baby locks, just rinse it off right away. Also, for baby locks, only add about 1Tbls ACV to the mixture.
As for the salt spray. If you use it, don't leave it on your head for more than an hour or 2. Spray it on the same day you are going to wash your hair and wash soon afterwards. If you leave it on long term, it'll dry out your scalp and hair drastically and make you itch out of control.