DNP is a very effective and efficient tool to cut body fat. In fact, it's one of the most effective ways....
BUT!
Mastering diet should be the absolutely first thing you do. Your title asks for lessons learned, I have two:
1. If diet isn't exactly where it should be, you're just wasting money and time for lackluster results. DNP isn't for the obese, nor will it suddenly take someone from 15% down to 9% in two weeks. Add to the fact that the most optimal dose is that which is close to a lethal dose for the individual - it's a very real risk.
HOWEVER, it is less toxic to the human body that acetaminophen. That is a medical fact. The difference being that people don't take acetaminophen by the handfuls to try to lose weight either.
2. Don't for the love of God mix it with tren. They both have a profound effect on cardiovascular ability, and I found myself on the verge of passing out every leg and chest day. This makes cutting rather difficult when you can't breathe effectively enough to raise that heart rate enough to burn those calories.
DNP isn't the bogeyman, but it IS one of the tools in our toolbox that can certainly kill you... Or make you blind via retinopathy. Be educated, be careful, listen to your body, be prepared, and be safe.
My .02c