What’s your vote for the most ridiculous, overpriced, and useless tweak?

Schumann generator update:

I dont use the S.G. like most people do... Not only it generate some frequencies, the Schumann one, but he S.G. is really an apparatus to improve the effect of stones and crystals... I use Shungite mainly with other stones that are there to compensate one another effects they produce to gain what you want to hear with your particular speakers and gear....

For the beginners try a piece of shungite under the S.G. or on top of it but without contact with 4 improvised feet I cut myself, it will greatly enhance the effect of the S.G. to the point in my audio system to put it on another plane of details...remember when I speak about the effects of something that all my audio system is tweaked with a connected grid of multiple kind of crystals and stones...

What is S.C.? 

I have already experimented with the sonic effect of around 20 kind of stones and crystals... They all induce different sonic effects like tubes in an amplifier but greater sometimes... It is very easy to correct all degradation to gain the better with any of them because they collectively correct themselves in a synergetic collective action after the first experiments...At the end the effect is astounding and compare musically to nothing else...Variation of ALL particularities of sound can be gained...Imaging, dynamic, timbre modification, body, transparency, 3-d sound effect, with speakers or headphones etc...No upgrade of gear will give you that at a relatively low cost...The S.G. is like an amplifier for stones effects...I will never need to upgrade my very good but modest in price audio system...

Before all these experiments with tweaks, with exactly the same dac, amp, amplifier and speakers, I never knew what my pieces of gear was able to deliver...I was not satisfied, even if my basic gear is good for all reviewers and people who already owned  them... Most  people dont have a clue about their audio system potential by lack of cleanliness of source, power supply, conditioner, lack of room treatment, lack of vibrations controls, lack of cleanliness in the house electrical grid, lack of a minimalistic controls of RFI. or EMI....I know that I was one of them no more than 2 years ago...