To keep pages in my art journal from sticking together, I use parchment paper. In the states, parchment paper is sold at the grocery store in rolls in the baking department, with the aluminum foil and wax paper. It is usually white or brown. Put parchment paper in between the pages and put it under a bunch of heavy books overnight. It can take a few weeks to truly dry.
You can just keep re-using the paper, and any paint on the parchment could transfer to your page. The yellow on the page below was from used parchment. I don't mind, but you might.
Hope this helps in your quest for unstickification.
Can you see me jumping up and down? My interview with Dawn DeVries Sokol is on Create Mixed Media! Wowee zowee!
Note: be sure to read the comments for more details about the unsticking process...