based on my understanding of an a'dam, it essentially forces a woman wearing it form an involuntary circle with another woman.  which cannot be done without the use of the ter'angreal.  consider this, suian and leane were able to form an incomplete link with moghedian when they were stilled.  both women could still sense the source, but not touch it.  I think that means the ability to sense the source is half of the requirements to fully use the a'dam.  additionally when mistress anan was temporarily linked to joline the negative effects of the a'dam were still on effect, ie joline began to suffer pain when they started to walk.  this implies that to negate the negative effects of the a'dam, a woman wearing the bracelet must be able to both sense and channel the one power.  additionally, the a'dam has no effect on a woman who can do neither.  so in a shedding or far madding, where a woman can neither channel or sense the source, the a'dam should work exactly as if it was placed on a woman unable to channel, which would mean that the ability to control to leashed woman and the negative effects of the a'dam would be negated.