Rand, for example, could access the True Power to destroy the a'dam around his neck, because it seems the only thing the a'dam affects is your access to saidin or saidar, not other capabilities. He could even form weaves that would directly harm the a'dam...once again, because all the a'dam seems to affect is your bodily control and your access to saidin or saidar. Slightly flawed example, but it does show that the specialized construction of the a'dam and sad bracelets can only limit channelers from using saidin or saidar.