Most of the work I’ve done with this has been on targets I have little ability to gather information about, so in most cases I don’t know how effective it has been. In the few cases I have used this in situations in which I can find out if there has been a result, its been very hit and miss.
However, there are a lot of people here who have got really good results. There are quite a few threads on this book and it is worth reading them.
I found this one very interesting back in the day (the OP is no longer on the forum so wont be able to field any more questions though)
Mike B’s Djinn Working Journal - Journals, Group Rituals & Free Readings - Become A Living God