Yes, do twy the Tween Annie.
Of all the steps/ingredients/techniques used to coat fixed-out baryta paper, Tween is by far the most important.
It chemically makes "water wetter". It lowers the surface tension of a solution and thereby permits a faster and deeper penetration into the surface of the paper.
You can order Tween 20 (there are a couple of kinds. 20 and 40 I believe. I use Tween 20) from Bostick and Sullivan. Check the yellow pages for Vancouver though. I bought mine from a local chemical supply firm (Anachemia) here in Winnipeg. I believe the stuff is used in medical/bio labs so it is not that hard to find.
If you can't find any locally I have about 2 lifetime's supply of it. Let me know, I can send you some. You will wonder how you ever got by without it!