(I'm familiar with salt finish, have specified it many times, just not in rainville. Consider slime as well as freezing..)
On walls, you may or may not also want a seat wall - those are usually about 16-18" high and do act as seats. Could be block finished with, say, old brick, if brick steps are nearby. Or stucco to-match house with some kind of smoother cap, perhaps stone or brick. Hmmm, or maybe smooth finish matching concrete color.
I'm don't think it's additive in Boomer's yard, though maybe on one side... but it can work in some gardens. If you do a higher wall, which I'm also not sure about in your case, Boomer, maybe, maybe not - I'd have the finish match the house precisely so it works like a fin wall.
