I’ve used cat whiskers alot and always had a quiet bow. One of the simplest and best silencers I ever used was showed to me by an old-timer. It was a 1/4 inch slice of a bicycle tire tube. Like a wide rubber band. He looped it through itself on the string an cinched it tight.
The biggest thing, no matter what you use, is where to tie it. I think there is a thread on here that mentions something called Heterodyning. Basically, think of the vibration of the string and now break it into different sized segments to cancel each other out. Measure the string and divide by 4. tie one silencer at this measurement from the tip of the top limb. Now divide the total string length by 3. tie the other silencer at this measurement from the tip of the bottom limb. You basically create 2 different vibration frequencies that effectively cancel each other.
Sorry for the long winded reply, hope it helps