A myth I have heard is that if you place your cellphone in a mylar type of a bag it will not receive or transmit.
One could try it with a resealable baggie that you have several layers of a space blanket wrapped around it.
I’m surprised there isn’t a market for a portable cell blocking travel case, I know I want to make my own.
Might be worth trying.....on the other hand, how would you know? LOL!
Of course if I were really worried about this kind of stuff, I wouldn’t be driving around in my car with OnStar on board...
Like I said—if I’m important enough for them to bother with, let them come and get me. I’ve lived a long, wonderful life......