Filling voids

I believe the name of the expanding foam sealer is "Great Stuff" I've used it for years and have had great luck with it. One thing I do is to make a dam out of cardboard, I'll cut it to fit around a pipe that comes out a block wall so there's no big blob on the outside with the foam expanding inside the wall. "Good Stuff" is a song by The B-52's.

Great Stuff comes in two versions; one expands more, and the other expands less. Both of them are hard to clean up.

DAP has a similar product that's water-based. I used it for the first time a week or two ago, and it cleaned up with a damp rag, even from brick. Downside: It took a long time to cure, and it cost twice as much as the Great Stuff.