If I understand the author's premise correctly, the fallen angels who were lost in the flood were bound and contained in "Hades", but the spirits of the offspring are the demons that plague mankind today, also known as "familiar spirits". He agrees with you (and so do I) that these are the same spirits that may show up in haunted houses or any supernatural experience (ufo's i.e.).
He also states that the Nephilim appeared after the flood, i.e. the "giants" in Canaan (Num. 13:33) which is also referenced #5303, fallen ones.
"And there we saw the giants (Nephilim), the sons of Anak, which come of the giants: and we were in our own sight as grasshoppers, and so we were in their sight."
In my website, www.preparetoleave.com (in maintenance mode right now, so please be patient) there is a section devoted to looking for new revelations in the word. Those things that were "sealed" for the time of the end I believe are being revealed. Like you said, you have to seek them out with a lot of prayer.
"Those things that were "sealed" for the time of the end I believe are being revealed. Like you said, you have to seek them out with a lot of prayer. "
The Gnostics were a heretical sect that believed they had secret knowledge, too.