You also need to plug it from the pool side so the water doesn't get into it and leak from that side.

Yea I got a cap that will screw into the outflow jet with no leaking.

If you close off the side of the pool you may not get enough circulation and that leads to a whole new set of issues.

Didn't even think about that part, yea seems like a no-go.

Fair enough on the getting stuck possibility, but I have since found this product. It's designed for the purpose plus the outflow will still be usable if the thing works. Any thoughts on it?

I'm hesitant to spend the money and/or time to fix it properly; it's up in the air whether we'll still own the place a year from now, and I'm pretty sure we'd have to remove and reinstall at least a small section of brick.