Anyone ever set up sprinklers to help compaction?

Hey everyone, Anyone ever set up sprinklers to help compaction on a job with really dry Sandy dirt? Actually it's clay but during the height of dry season I'm not getting much cohesion. Fixing a tight hairpin turn switchback on a customer's driveway. Already dug into the wall about 20ft up to open up as much space as possible. Had to build a big dirt ramp to be able to reach the top and knock the slope back a little. Now the other option is to fill on the down side of the driveway. Cut a bunch of saplings and brush and threw it down to act as a temporary retaining wall while the dirt solidifies. Moderate results, but now I've got tons of loose sandy dirt that could burst the dam and flow down the hill. I want to solidify what I've got, and perhaps fill more if I could. During the wetter times of the year I don't think I'd be having any difficulties. Hoping if I set up a sprinkler for a few days it'll help. Any suggestions? Careful about waterlogging it? Few cycles of soaking and drying? What are y'alls experiences? Thanks!