There are a few firms selling it here in Australia.  The first one I got it 
from ($8.50 for 225g) was http://www.xylitol.com.au/index.html but there is 
another company www.sweetlife.com.au 
I paid $13 for 225 g of Perfectsweet from the second company through my 
iridologist, but I see it would only have cost me $8.95 on line, and cheaper in 
bulk.  
When I spoke to the first company, after failing to get it locally at the time, 
the boss said they had tried to make their own nasal spray, but ended up 
getting Xlear from America because they couldn't do it as well.
I see there is also a firm called Bionatural selling Naturally Sweet xylitol. 
http://www.bionatural.com.au/default.asp?newsID=90271
In WA http://www.msm-australia.com.au/site/711782/product/XYLITOL0250 is in 
Kwinana.  Prices on special at the moment, I see. (They also sell "High 
Voltage" CS for $21 odd and MSM bulk.)
Hah!  See what happens when you do a bit of research?  I just ordered Xylitol 
and MSM off these guys.
Rowena