You only need one strand but some guys like to use the multi-strand like a small brush. The single wire jet cleaning tool works great too. It’s a single wire wrapped around the hinge of a small plastic tub which doubles as a storage container for small things like metering tips or earplugs. Both feature ultra thin stainless wire, perfectly sized to clear the orifice of our tiniest jets.
All you do is unscrew your jet from the jet manifold then unscrew any check valve assembly (do it over a towel so the parts don’t roll too far). Then you simply poke one strand of this special wire into the orifice of your jet from the outside to clear the obstruction. Rinse the jet with clean water and hold the jet up to the light to see that you cleared the orifice. Reassemble the check valve assembly, reinstall the check valve assembly and you are done.