I haven't read this, though I am sure someone else must have thought of it first. I'm trying to reduce residue use while training imbuing (and who isn't?), with my current skill in low to mid-70's. It's tough using only one residue per try at this level... until it dawned on me that I can imbue runic made weapons. So, I grabbed a DC runic hammer and made a batch of GM daggers and tried imbuing them with luck. I found that I could imbue about half of the 50 I made, and had to unravel the rest. The rest I could imbue with +1 luck and keep the success rate in the range of 30% - 60%. I went through about 200 residue and made 3+ skill gains in a few minutes. Next, I am going to try imbuing the low level loot that I have been unraveling.