You may want to get some bow hushes for the limb slap. They are wool and work well. Also, a piece of moleskin will work wonders.
The position of the silencers are also important. Art has a good method of finding the correct postion.
ORIGINAL: Arthur P
Another way of finding the sweet spot for silencers... String up your bow and sit in front of your computer. Find a web page with a light background. Hold the bow up in front of the monitor, so the string is backlit. Then twang the string and you'll get a strobe effect from the monitor so you can see the string oscillations. Do it in several spots on each end, and you'll see the highest point of oscillation. That's the best spot to put your silencers.
And yes, I DO have too much time on my hands.