Unless you take the battery out how do you know your phone is ever off. It doesn't just have hardware toggle button probably. So you'd have to take the battery out. Well then isn't it easier to put it in a Faraday cage than mess with the battery.
As soon as you take it out it can transmit everything it captured while in there.
This thing is useless for a cell phone.
Again, this pouch is useless.
In order to turn the first into tracking the phone has to either do the inertial tracking itself (possible but computationally expensive and it diverges pretty quickly unless there have been some major improvements).
The second requires some luck involving an identifiable sound marker some where in the recording then the processing power to cross reference everything.
It's a mistake to confuse imperfect with useless.
Just turn the phone off. Or really just the GPS off since that's the only thing this thing blocks.