That salt is fine- be sure to test your salt level BEFORE adding any.
Then add about 3/4 of what
PoolMath calls for & re-test in a day after it’s dissolved & circulated & then add what is necessary to achieve your goal.
Don’t turn on your swg at this time as a slug of highly concentrated salt water will damage your cell. Be sure the salt has circulated for a day before turning on the swg.
That acid is ok but it’s twice as expensive & 1/2 as potent as these

Muriatic acid should be used for ph control
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You do NOT need to clean your new cell with acid - A new cell should not have any scale buildup anyway.
Hopefully by maintaining
Recommended Levels
You will not really ever need to clean your cell with acid. Doing so removes some of the precious coating from the plates which lessens its life span.
If u happen to notice scale build up when inspecting it the first thing to try is using a popsicle stick or credit card to gently remove it. Then figure out why you got scale in the 1st place & correct that chemistry issue.