I have 2002/2003 Salomon Dialogue boots that need new laces. Every
lace
that I've tried is either too thick or too soft for the Salomon
locking
mechanism. Where do I find a lace that works? Or do I give up and tie
the laces?

You should be able to get a new pair of laces plus locking mechanisms
for about US$6 from a Salomon dealer. They might need to order them
for you though, they may not stock them.