Chemical Questions: Sodium Hydroxide and TSP

[NJWashingGuy 31]

I am unsure of a couple of things when it comes to the chemicals needed to do certain jobs properly:

1. A local chemical distributor sells Sodium Hydroxide liquid in 25% and 50% by weight in membrane and diaphram grade. Which one would be more suited for oil removal on concrete and general cleaning of masonry surfaces and as the main ingredient in a stripper for oil based wood care products?

2. This same distributor sells TSP in anhydrous form? Is this what I should be looking to use as the product for part of the Apple Sauce roof cleaning mixture?

If anyone would like to share their formulas or if anyone would be willing to educate me I would appreciate it. Also if anyone does not want to post this info, you can PM me as well or call the business number, but I am working my other job tonight. I will try to call back from my cell phone.

Thanks in advance for the help. Mike