Indeed you can take away some of the plant material, so to have a 'more' concentrated residu. But this will probably only make it like 0.1 times stronger, making an extract would be far more sufficient. But that's just what I think, and I'm only trying to help.
I've read some great tek's on making Sally blotters, it's quite simple and you trip a lot longer(+/-45min.). Never tried it myself though, but that's what i'd be doing if I had some dry normal sally leaves.