Gore-tex is a membrane....it is always waterproof and breatheable. Gore-tex has no "water-resistant" qualities. If it gets clogged by dirt, liquid detergent, etc. its more difficult to restore. Some chemicals will clog the pores permanently.
The shell itself can be restored by the washable liquids that you mention. The low-heat dryer helps spread the formula more evenly. Also can be used to temporarily restore some beading properties in slightly worn outerwear w/coatings. I use mainly NIKWAX, but nothing is quite as good as the dwr that is applied at the factory.