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

My vote: Furutech Outlet Cover 105 NCF $220, with “special crystalline material that has two “active” properties.” https://www.thecableco.com/outlet-cover-105-ncf.html

Here’s two tweaks that might surprise you. SONEX foam panels and lead shot. Two of the worst materials ever foisted on gullible and easily influenced audiophiles. Lead seems like such a great material for audio - massive and dense but not too hard, not too soft! 😬 As for SONEX who could doubt that recording engineers know all about sound? 😩
@mahgister - improve your SGs even more with Cream Electret and Silver Rainbow Foils, free samples from PWB Electronics, enough to treat them all. Tell em Willie Boy sent ya!

Just found a new one. Primary control tonearm. $32,500.

Seriously? At first I thought it was criminal for what they are charging but then I realized that some fool will buy it on their own.
@devilboy that thing might be a lot of things, but I wouldn't consider a tonearm a "tweak."  Can't you get one custom made out of a human femur?
With $105,000 turntables and $16,000 cartridges that price for a tonearm seems consistent. Say, isn’t that the tonearm Michael Fremer owns? If low weight and stiffness are prime tonearm attributes how about a graphene coated balsa wood tonearm?