Follow up and conclusion...
So I went out and bought a scale to figure this thing out...
Results:
2 "solid" oz of salt is just that, 2 oz of salt.
2 "fluid" oz of salt is about 2 and 3/8 oz of salt.
Conclusion:
It really doesnt matter which method you use ( I feel ), the results are too close to really matter.... unless you are mixing a large quantity of plastic, but even then, a little extra salt never hurt anyone.
Hope this helps.....