What is the Silliest Accessory You Have Ever Seen.

Superglue bowling balls to the top of your speakers. Fingerholes down and forward facing of course. 

I’m only slightly ashamed to admit that I recently bought a Schumann frequency generator, albeit one of the cheap models.  
I’m always willing to be wrong, and hey, I bought it, but it does seem to me to be one of the more scientifically dubious tweaks.

But for less than fifty bucks, I have a nice little wood box with a red light!  And heck, maybe it does something...

@daveyf point taken. But then what justifies the $1,700 cost? For, in essence, a few pieces of curly wood on a stand?

"But then what justifies the $1,700 cost? For, in essence, a few pieces of curly wood on a stand?"

Someone's willingness to buy it?

@simao One could ask the same question about what justifies the cost on numerous pieces of gear in this hobby!
If you look at how the Shakti’s are made and what goes into the various aspects of the product to get it to market, I can see where they are coming from with the price, certainly at least as much as a ton of other gear that carries pricing that at first look seems "over the top" ( and most times certainly is). The Shakti’s work well as acoustic treatment...more than can be said for a lot of other gear that is also pricey, and offers less for the $$.