I cleaned my own Silhouette blinds and saved $700!
I posted this in the Decorating forum and wanted to share.
My initial fear of doing this was removed after we had rain soak one and it didn't make a water stain. Since they were 100% polyester I tried it with the carpet vac and it worked.
Here is a link that might be useful: http://ths.gardenweb.com/forums/load/decor/msg0716365932117.html?17