sealing brickwork

Basically what it says on the tin. The drainage pipe for my washing machine is sitting loosely in a hole in the kitchen wall (see picture). This feels like it's risking damp getting in and causing mould. My question is, what's best to seal it with? Expanding foam? Some sort of sealing/grout...

Has anyone any recommendations for sealing exposed brickwork? Interior. I’ve some old brickwork that I’d like to keep, read about pva, but didn’t think that would last well? I don’t want the brickwork shiny. Tia