I've been doing a little experimenting lately so this topic is right up my alley.
I have just recently been experimenting with different arrow spines since both of my two bows shelves are cut 3/16" past center so it allows me to shoot quite a few differently spined aluminum arrows.
When I was shooting my 66", 42# @ 30" recurve (12 strand Dyna97 bowstring) with a 32", 2117 arrow weighing 602 grains, the bowstring didn't need string silencers. Bow was whisper quiet with no bowstring noise.
Two days ago, I wanted to see if I could shoot a light 2212 target arrow out of it. After getting a 32", 2212 arrow tuned perfectly with an overall arrow weight of 476 grains, the bowstring noise was very loud. I put on a pair of rubber catwhiskers and it helped a little, but my wife, who was standing 20 yards from me said the bow was still loud to her ears.
I then put on a pair of homemade yarn puff silencers I made and the bow instantly become whisper quiet. No string twang noise and my wife couldn't hear any noise at 20 yards.
String silencers do work. Do a little experimentation on your own and you'll probably come to the same conclusion.