Contractors I know do not use these clips. I have never used them either. They are expensive unless you intend to reclaim them and the lagging boards. The design-build earth retention specialty contractors I know attach timber lagging to the flanges of the soldier beam with welded, threaded studs, nuts, and plates. Then, the lagging and the studs, nuts, and plates are left in place because the contractor, by then, is off to another job.