The "super epoxy" worked well in the sense that it stayed exactly where I put it. At the thickness I was applying it, however, it was much more opaque than translucent.
I also tried the hot glue, and I have to say I like it a lot. Like the "super epoxy," it stays where I put it. Dispensing is precise, because it comes out of a hot glue gun, which can be had for $1. It also rapidly sets and can be put in service within minutes. Plus, the glue sticks are very cheap (an order of magnitude lower cost than an equivalent volume of epoxy). Plus, non-toxic, and no mixing issues. So, I did some test units and put them outside to see how well the encapsulated electronics will weather. I used some cheap solar lights that I know are prone to rapid corrosion as the test units, so it should flag a moisture penetration problem if one exists. It will be easy to monitor, because the light won't come on at night or will dim if it fails. Therefore, how well it performs remains to be seen, but I suspect it will be good enough for above ground, especially if used inside the shell of another container. Well, time will tell.... I may look into polyurethane hot glue sticks, because those should be thoroughly waterproof if it turns out the cheap glue sticks just aren't good enough.
Yeah, there is spider webbing from the glue sticks, but I found it to be only a minor nuisance. Also on the negative side, at the thickness I'm using it, it's much more opaque than translucent. Furthermore, because of possible shrinkage, I don't think I would trust it for an underground (earth contact) installation. For that, I think I would go with what EdM is using, since it seems that he has proven that particular epoxy really works well even when continually submerged in water. The PC Clear might work, but its in-use performance is more of an unknown (at least to me), and it might take years for a bad choice to reveal itself as such.
Anyhow, I'm still open to alternate ideas, and I hope others will share whatever they have found works well for them.