That doesn't mean a thing if it doesn't actually bond to the surface. I made the mistake of using some 2-ton epoxy on similar plastic once, and it fell apart by itself the next day. You may get just enough adhesion to get the job done, but it typically takes some pretty advanced adhesives to actually make a solid bond.
It has held for 3 years, I doubt it is going anywhere now. That's why I specified that name, not just a random adhesive.
I water tested the silicon patch. It is not bonding only to the surface. The wall is nearly an inch thick, and is not smooth inside the hole, so it has alot more to grip onto than the plastic wall. I will see how it works for now, and probably change it out after a batch or two. I was considering just getting a stainless bolt, 2 washers, and silicon orings, and using that as a plug, that I know will last.