Hey, Mark
THANKS for renewing my attention to this!
What you'll want to do is use hydrolic cement (Waterplug or similar) on the wet side of the wall. (I'll give a couple of tips in a minute)
On the outside of the wall, you want to support the pipe, so that it stays in place and I like to seal the outside portion with caulk. Apply the caulk as per instructions, i.e. clean and dry and proper temp). This is a back-up for the hydrolic cement.
Hydrolic cement can be a BIG pain to use. You only have ~ 5 minutes to mix and apply it before it ~fully sets up

For it to be used properly, bevel the edge of the hole you are filling, if you can rough it up, to give it a better hold, that's preferable. Mix it in small batches
and don't make it so wet that it dribbles out of the hole and runs down the wall. You can either use a pastry bag to squirt it into the hole or a margin trowel. If it's setting too quickly for you to place and smooth, it can be 'cut' with regular Portland cement, however, this weakens the final product!
What I would like to know is what you will be using to accept the return jet/ eyeball - it's easier to just have a F/A, but a F/A threaded adapter with a flange would probably look better. Let me know what you're gonna use and I'll do my best to 'walk' you through it.
