I think the 99.9 percent reference was in regards to parsing a definition as to whether "coupling" or "decoupling" is involved--that might not be important to some people. Surely most people want to understand how and why an audio accessory works and how it applies to what they want to achieve (though might not care about "some" of the whys and wherefores) before investing their hard-earned cash.
With isolation, products that use materials of high integrity and are themselves primarily sonically neutral will not be so prone to system dependence (as evidenced by an extremely low product return rate). Bringing out the best inherent potential of the gear and most faithful rendering of the originally recorded event is the goal.
Every audio system is unique in regards to vibrational environment, interaction with system synergies vary (such as complementary aspects), as do personal taste/preference. So one person's result will not necessarily apply to the next, or may apply equivalently but to a greater or lesser degree. A preponderance of the evidence from customers can be helpful though. Regardless of all theory, research and testimonials, the sonic end-result is always most important.
Steve
Herbie's Audio Lab