> If what you are communicating needs to be guaranteed to never be crackable, you only need to use the oldest and most secure way of communicating before the days of internet and computers: short wave transmitted one time pad codes.

I'd say using a dead drop is probably even older and more secure. I don't think it'd attract any extra attention unless you're already being followed.

A numbers station is really only useful to a particular use case that seems exclusive to nation-state spies: you don't care who knows you're transmitting, but you need the message and the location of the recipient to be absolutely secure.