trying to use dump() with Firefox on OS X

I'm trying to use the javascript dump() command with Firefox under OS 
X, but for the life of me I can't figure out where it's going.

I've tried variations of running 
'/Applications/Firefox.app/Contents/MacOS/firefox[-bin]' with 
redirecting stderr but no luck. I've checked all of the common system 
and console logs--no luck.

I've tried googling my heart out, but no luck. The best I've found is this:
http://tinyurl.com/2wnkf [groups.google.com]

Here is the important part from the above link:
"Dump() commands are written to the console.  To bring it up on windows
you run mozilla.exe -console but on the Mac I'm not sure how they do it,
although I heard they came up with some way (Probably through drag &
drop or something)."

I've also tried playing around with './firefox -console' but I still 
can not get anything.
Is 'dump()' supported on OS X? Can someone help?

thanks,
josh.