Baking soda inside PlayStation 4
Solution 1:
Turn it off, and try and Hoover it out, the only problem I can anticipate is that if theres moisture, the baking soda will absorb it but hopefully enough didn't go in to cause any major problems.
Solution 2:
One thing you can do, is take the PS4 apart and then use an air duster to suck up the baking soda out of the ventilation.