Not being familiar with it, I looked it up. I don’t know that I would recommend it, personally. We’re not supposed to jump into intense spiritual practices. There’s a two fold danger of burnout if we fail and prelest if we succeed. Eastern Catholics have our daily prayer rule that is formed by our confessor who shapes it according to where we are at. He also modifies it, as needed, to combat specific sins we struggle with. It’s similar, in a low key way, to what exodus 90 is setting out to do (minus the fraternity part). It’s all about prayer and fasting. But the idea is to start out really small. Your confessor assigns your rule of prayer and you faithfully adhere to it, not doing more or less than what is prescribed each day. More is added over time (could be weeks, months, or years). The idea is to make slow but constant progress vs huge leaps followed by lapsing. Probably not the opinion you wanted to hear, but I figured I’d share it all the same. These programs are certainly well intentioned but they are hardly without great spiritual dangers.