I apply the spray glue to the pattern, then apply directly to the wood. Once I'm done I do as Travis said and use mineral spirits and it lifts right off.
I to use both blades and don't have a problem with oil on the FD blades. For my portraits I use #3 or 5 reverse tooth FD blades. I use the FD blades more than the olsen, to me they seem to cut more aggresively.