Q:

Has anyone got a proven recipe to attenuate wi-fi with a Faraday cage?

I need to put a domestic wi-fi router in a homemade Faraday cage that will severely attenuate the signal. Has anyone actually DONE this?
There is lots of good advice of what should work, but  few reports of what actually did work.
The nearest, on Youtube, is someone putting the router in three big nested heavy metal trash cans. That works good, but I've got no room for kit that bulky. 
A great-sounding suggestion is to cover a box in 2 layers of aluminium foil, so there is high capacitance between the two layers.  I tried this and it didn't work, maybe because I re-used old foil and it wasn't flat enough. 
In general aluminium foil is useless - it is like Wile E. Coyote and the Road Runner, the signal just laughs at it.
Perforated metal sheet a few mm thick is meant to work. If no answers here that will be my next attempt, but I'd love to know if anyone has actually done this in any way.
Many thanks 

A:

A common microwave oven is specifically designed to block the frequency band used by wi-fi, bluetooth, cellular data networks, and various other wireless communication protocols. This is because the microwave oven operates at the same frequency band; that's why microwaves can interfere with wifi.
A cheap microwave, or even a non-functional one, is probably the easiest way to get a good Faraday cage of this type. Either put a battery in the microwave with the device, or cut a small hole to feed a power cord through; the hole will cause leakage, but it shouldn't be too much.
As for being a proven recipe... Well, the fact that you don't feel hot standing in front of the microwave is evidence enough, no? If you need more, just stick a cell phone in the microwave and try to call it. It won't ring. (as mentioned above, cell phones and wifi use the same frequency band)

