Pondering that Secret Keeper thing

[melclaros]

No: HPFGUIDX 77584

I just don't "get" this Secret Keeper arrangement and am wondering if 
anyone else has given this much thought. Yes, I understand the *idea* 
behind it and that was illustrated nicely when Harry read the address 
of 12 Grimmaud Place off DD's parchement and the place "appeared" to 
him.
My question is this, once the Secret Keeper imparts his information 
to you, are you free to pass it on? I'd say not. It was made pretty 
darn clear that ONLY the Secret Keeper would be able to impart said 
secret.
So, following that path, what happens if you try? (Say Mundungus is 
expecting a delivery of dented cauldrons and wants to give #12 to 
UPS.) Will the person you are speaking to just hear jibberish? See 
you moving your mouth but nothing coming out? (Flash on that annoying 
Verizon guy "can you hear me NOW?"). What if you tried to write it 
down and hand it to someone. Would the paper be blank or would you 
unkowingly hand the person you're trying to tell a tic-tac-toe 
diagram? 
Do you suddenly "forget" either what you were about to say or the 
whole secret?
Or maybe you'd just be struck dead on the spot. Any speculation?

Melpomene, who should have better things to think about.