This book has many wonderful techniques that you can use for clearing your energy field. Some of them are gentle and others can be really intense, but you are given step-by-step instructions for each exercise as well as a description of what each one does.
Though the workbook is based on theories of space beings who are contacting us to help humanity evolve, you can still make use of the techniques whether or not you believe in Pleiadians or Sirians. Every exercise is designed so that you can call on any deities or angels that you wish. You do not have to call on anyone in particular if you do not wish.
The thing that I love about these exercises is that I can take any parts out which don't follow my belief systems. The book is written in such a way that you have the freedom to take whatever you need from it and leave the rest.
With this book, you can teach yourself how to ground, how to balance your mental, emotional and spiritual systems, how to clear your environment or your aura of parasitic energies or discordant energies, or release old, inauthentic beliefs that don't serve you anymore. You can also cut psychic cords with people and things that are pulling on your energy.
I will say that the book probably works best when you have the time and patience to do at least one exercise a day or several times a week. I feel I should also say that when you first start doing these exercises, you may find yourself going through a clearing period afterward. Every person is different and will react to the exercises in their own way, but I found that when doing chamber sessions, I tend to feel disoriented and slightly emotional the next day, but on the second day, I feel great.
My advice would be to either build up from the beginning and go through the book step by step as Amorah suggests, or if you prefer to skip ahead, to test things out and see how you react to different exercises so you'll know which ones relax you and which ones create an intense clearing process. If an exercise is too stimulating, you may not want to do it near an important event like a job interview or presentation. Or, you may benefit from doing it several days before the event so that you clear your aura, but you've already gone through the reaction process. I am very sensitive to energy, so when I do the exercises, I have to allow for an extra day of clearing afterward.
Oh, I feel I should also mention that the exercises are written in such a way that if you have a tape recorder or a friend who is willing to read out loud to you, you can meditate and visualize without having to open your eyes to read the book or to memorize the whole session beforehand.
Amorah also has a second book which has some great techniques in it. The Tantric Workbook seems more intense so it's probably a good idea to start with this book first. I've noticed the effects of exercises from the Tantric book pretty much right away, but I think doing regular energy work or doing the Pleidian Workbook frequently helps to prepare your system for the new techniques.