If you press on the foil, the hole may reveal itself as a small dent. I don't have a Strat body laying open at the moment, but it seems to me the hole is about an inch and a half back from the front wall where the claw screws in, and about halfway up the sidewall. I doubt it's a hole the CNC machine does, so the position may vary, but that's where I'd be looking for it. Get a finishing nail or something like that to poke around with.
Another thing to consider is that since the foil shielding is useless, if you have to pull it back to find the hole by sight, you're not going to hurt anything.