^Exactly! I read that thread by the way - fascinating. It's something I definitely have to try. It seems that your experiences were more or less neutral, which is something that I would expect of the tank depending on what you wanted to get out of it. Having been fascinated for quite some time by the realms of so-called 'astral projection' and other out of body states, I believe that that neutrality would be turned to the positive for me. In some of my astral states (sober), I have experienced some of the most euphoric existential states of being. I believe that the tank could very much enhance that ability to dissolve and experience what it is like to exist as pure light.
Maybe if you don't overthink the state too much, and just try to let yourself exist there in that moment, that could be the key to the experience. I can imagine bumping in to the sides and letting my awareness become distracted by telling myself that I was expecting that to happen etc. It seems that meditation techniques could very well fit like a glove here.