Just lightly spray. I learned the technique from a Tim Holtz video, the link is in his website. The ironing part is my idea. The background (Broken China) and the tree and grass started as white paper.
Doing this on the edges of paper to make it look like fabric is SO easy and fun! There are step by step instructions on the Swirlydoos site - pictures and everything! I usually bring mine to the sink and wet it with my fingers so I have more control over where the water is going. Inking the edges first with TH ink also gives a cool effect.