Here is the Amazon link for the cheap set I bought. But you can spend much more.
https://www.amazon.com/dp/B0DPW4VJX4?ref=fed_asin_title&th=1
1. This is a good question. The chisel will take you down as far as you want/need to go. The picture I showed was all the way down to the clay but I have found that you can leave a very thin layer and as long as it is smooth and solid, it will still work. That is what I did to most of mine. The reason is the when you go all the way to the clay, you run a higher risk of making a gouge in the clay. But it is your choice. See the pictures below. While the one on the right may look like it has a lot of paper left, it is smooth to the touch and shiny and is perfectly ready to accept a label.
View attachment 1692593
2. I had never tried murdering Milanos so I just took out a couple sample Milanos I have and you won't need the chisel for those. Just make a small slice in the label and it will peel right off. But slice lightly as it will leave a mark if you are heavy handed. See pictures below. Heavy on the left and light on the right.
View attachment 1692592
Let me know if you have other questions.