This is from one of the older "paranoid noob starsan fear threads." 
Also...ever here about covering your ass with legal boilerplate in case someone does something stupid???
People are stupid...and Lawyers are smart enough to cover their clients ass with warnings.....like warning on cruise controls in campers, not to engage them, and get up and go to the bathroom...or other fun things like these...The Darwin Awards
As you say, these warnings are for the undiluted Star San product. There is no concern once it has been diluted properly. There is less phosphoric acid in properly diluted Star San than in a glass of Coca Cola. So you have to ask yourself, would you take the same precautions with a glass of soda pop? If you answered YES, then rinse away!
:fro:
Also...ever here about covering your ass with legal boilerplate in case someone does something stupid???
People are stupid...and Lawyers are smart enough to cover their clients ass with warnings.....like warning on cruise controls in campers, not to engage them, and get up and go to the bathroom...or other fun things like these...The Darwin Awards