Maybe I am just too lazy or skeptical to try it, but either way for those of us shooting high intensity rounds it would cost a lot more than the $11......
First one would have to consider how many shots would it take to verify?? Lets say two three shot groups at 500 yards to establish a baseline for performance. (that is pretty much a minimum, one group seldom proves anything, two is only just a little better)
Then how about we start with the de-resonator 2" from the muzzle end of the barrel, fire two 3 shot groups. Move it 1" back and fire another pair of groups, move it back another inch and fire another pair of groups, etc..............
Evaluate the results: Maybe we notice that 6" from the muzzle gave us two groups that averaged smaller than our baseline groups without the de-resonator. Now we need to fire another 3 to 5 sets of groups with, then without the de-resonator to see if there really is a difference........
$11???? Now I have fired at least 100 rounds of precision loaded ammo which took hours to load, had to clean my rifle barrel at least 5 times, burned up 100 rounds of barrel life in barrel that is only good for 700. Looks like a lot more than $11 to me.
Please understand I am having a little fun with this and only being half serious.
But, half serious I am....... often with things like the de-resonator or different primers, different seating depth, a little more or a little less powder we can fool ourselves into thinking we have hit the magic combination based on one or two fantastic groups. The problem is, we may later figure out that all it was, was a couple of great groups, not the holy grail. I have talked to guys who swear by those things, but when I quiz them about how they tested it there was no real scientific test at all, they just got a good group and became convinced it was the de-resonator.
Most guys who are competitive shooters or serious long range shooters keep very detailed log books. Everything is in there regarding the load, rifle, environmental conditions, etc. for every round fired from that rifle. That data is used to spot trends or as a basis for comparison. One or two 3 round groups seldom tells the whole tale.....
Don't let my being a skeptic discourage you from trying it. Just know when you do a post on how great the thing works that the skeptics like me will want to see a detailed experiment, not one 3 shot group...... or I for one will probably remain a skeptic.