I tried alcohol reduction but found it complicated and unnecessary. The key to copper matt is reduction. And what is used to reduce it with is not an issue. You can get the same results from newspaper as with alcohol. There is a window for creating the atmosphere needed to cause the results you want with copper mat. Most people pull work while it is much too hot. They miss the flash. Some have discovered that they can burp the trash can and get better results, but it is difficult and almost intuitive to find the right time to reintroduce oxygen into the can. Here is what I do which makes the process more measurable thereby giving more consistent results.
Fire the piece up to 1800 degrees F. Let it cool to 1100 degrees F. Pull it and place it in a can filled with newspaper. Let it burn. Notice the copper flashing on the piece. The copper flash, slows as it cools. If the copper is flashing too fast, you will not freeze it with a reduced atmosphere. Introduce more newspaper and notice the copper flashing more intensely as it ignites. This is when you want to clamp the lid shut.