How to Open a Bag of Charcoal?

I bought a new Kamado smoker about 6 years ago.  I haven't used it
yet, but I really like it a lot.  All my neighbors ask me what it is
and I like showing it to them.  They comment on how clean it is.  It
makes me proud to own one of these.

The problem I have with it is I can't figure out how to open these
bags of charcoal.  There's these two white strings knotted together
holding the flap closed at the top of the bag.  I've bought dozens
of bags of charcoal, but they all have these frustrating two white
strings at the top that no matter what I try, just won't come loose.

Is there a website that explains how these strings can be removed so
that I can get at the charcoal inside?  I've sent numerous letters
and called Kamado about the problem, but they never respond.  

I'd really like to try out this $1,800 Kamado.  It's so cool I just
ordered another one even bigger than the last one.  But I'd like to
figure out how to open these bags so I'll be ready for it when it
arrives.

Thank you in advance,

-- 
Kevin S. Wilson
Tech Writer at a University Somewhere in Idaho
"You can safely ignore Kevin in order to
maximise life's experience." --A. Loon, in alt.religion.kibology