I think you'll find that most "authors" tend to exaggerate their experiences and/or tailor their story telling to their intended audience. But then sometimes the experience can seem so real - the best way is to try for yourself.

If you have access to a quantity of silver wattle then by all means go for it.

NB I would also leave the Crowley-esque notions of Goetia type beings to the uninitiated - Entities are what the are, not what you expect them to be.