Muckey,
I think 78% is appalling... really, come on dude!!
Blenders sure - if your a beginner and have no idea about the real method!!
Get yourself a metal drum, similar to a 20L Ice-cream or oil drum. Load your whipper snipper with 2mm cord...
I think you can see where this is going... I have been using the 'whipper snipper method' for the last 17 years with out a fault. I have been averaging about 120-130% efficiency, which to be honest I reckon I can still get better!!
My curtains, doona, dog beds and all my socks are made from award sash's!!
I would strongly recommend something between 15-30 cc 2 stroke but you will find what works best for you...
Ok, the baton has been passed... enjoy those awards!!