MushaMan

I have used the expandable peat pellets before and have never had a problem with sterility in my cuttings. However, i don't really suggest those peat pellets, they tend to hold too much moisture and allow no air to the interior. No air, no roots. Recently I have only used one product for my cuttings. I bought these plugs at a nearby Hydroponics store, which are synthetic, and have rooting hormones and goodies built in. they even come premoistened. Since i switched over i have had alot of success. professionals make these things so we don't have to deal with it. i suggest finding somethign similar. Try nurseries, Hydro stores, etc.
As for the japanese maple, i am getting ready to take an air layering off a japanese maple in my front yard, i'll try and get pics on here when i do. Air layering is great, the possibilities are much greater than with cloning with cuttings.