Everything I have ever tried has made a difference of some sort.
Whether or not I cared for the difference is a different story.
I recently pulled a Furutech NCF Clear Line conditioner out of my main system.
They have a good reputation (as a brand name), and undoubtedly it "works", I think I just prefer the sound of my system without it.
Before I come on here and start bashing a product, or a brand name, or start slinging the term "snake oil" around, I at least owe it to myself to try it. I don’t have to understand how or why it works, I just need to try it and see if it works for me.
Isn’t that what being an audiophile is about?