Anyone using Sendust (Fe,Si,Al) to absorb stray EMI?

No, but I tried to order one A4 sheet from Mouser. It was going to cost $145 delivered to Australia, so I cancelled the order.

At that price, I hope it’s good! It does sound interesting...

Hi, whostolethebatmobile

Yeah, I found the Mouser pricing to be really high too.

If you're down under, I recommend the Oyaide MWA-030L (A4 size).
Not sure about your conversion, but it cost me about 50-60 USD.
You can get smaller sheets for half the price too. they also have a tape.
these smaller sheets are around 20 USD:
https://oyaide.com/catalog/products/p-3974.html

The only place on audio gear that I used the sheets is around the AC iec inlet or power supply. But mostly just in and around the AC outlets and breakers.
Here are some examples for those interested:
https://oyaideshop.blogspot.com/search?q=MWA

Stay away from the MWA-100 S as it is 1 mm thick, and I find it affects frequencies in the audio band. The only place you might find use for this is in a AC breaker box with all your circuits radiating and possibly absorbing EMI.

Thanks sonicshading - Oyaide seems much more reasonable for a trial sheet. 

Sendust appears to be a type of mu metal, aka Kool Mu, high permeability alloy used to absorb magnetic fields in transformer applications, for example, not RF, which is a horse of a different color. 🦓  Examples of materials that are good for RF absorption/shielding include high-conductivity graphene, carbon fiber cloth, copper sheeting.