Homer knows cleaning is important because dust, dirt, etc keeps paint from sticking well. If that happens then their house will look bad and they’ll have to paint it again.
Scraping off the loose paint should be done with a scraper, not a wire brush (it can cut in too deep sometimes). He’ll need newspaper and painters tape to cover the windows and doors with.
As for the primer Homer’ll want an exterior acrylic/latex-based one because they tend to stick better to brick. The actual paint can be either elastodynamic paint (great for filling in cracks and preventing them) or an exterior acrylic/latex-based one (great against mildew).
It’s a good thing he has a paint sprayer because that’ll cut his work time in half. Homer’ll only need a brush for the detail areas like the trim and around windows and doors.
Now he’s going to look at how to paint brick interiors.