From what I had heard, Blood comes with marking systems for a ton of decks, including a few that I cannot figure out how to mark besides scratches. Did DM take it off the market completely? Is there another place I could get it?
DM offers a book called How to Cheat at Cards. In this book, he devotes a fairly small space (10-14 pages?) to blood marking, and covers a number of various markings. Very clear explanations. You may have to buy it in PDF format at this point, look for it via google, Think hes charging ~$50 US for a download. The precursor book to The Mechanic and ExM DVD sets.
Another source which I believe delved into many types of markings in a similar way was Hidden in Plain Sight by Boris Wild. I'm sure you've heard of his decks, his book deals with the other marking systems as well. Plenty of info can be gleaned from either source.
If you're a DM fan, go find the HTCAC revised PDF (pretty sure it's served off his "fullname.co.uk" site but google will reveal the actual order link if you search well) link and order an instant download.
If you just need some info despite the author, the Wild book is pretty good and cheaper option too., Easily found on big A, often bundled with a Boris Wild deck.
Hope that helped