try tying your cat whiskers on with a wire tie, the type you use on a bread bag and move them until you get the optimal silence.
I really don't mess with mine to much I use two sets on my strings the set closest to the limb tips is approx 1" and the next set is approx 1.5 to 2" I just mark my string with a sharper at the 1/3 and 1/4 marks and place my silencers there. fold the string in quarters and mark and then fold in thirds and mark. I have found that for me string silencers work better for me towards the limb tips.
I really do not stress over the placement that much because I can get more results tuning the brace height, nock alignment and arrow spine/weight.