How to add small amount of dry cement to a rock walkway to hold rco

If they are rocking around it is because there is no support under them. Rocks were probably just placed on the dirt. They should have gravel under then sand on the gravel to provide stabilization and drainage. Dumping Portland cement on them will just make a mess.

Hi - are these small loose rocks or large stepping stone size rocks?

regardless of size or base support, sprinkling dry cement and letting rain supply water is not a good solution because You can't control the amount of water added. You can form up a frame, mix cement and pour (similar to forming a slab), smooth. Make about a 2" concrete bed, let dry and then set your rocks on this. After you are sure all is set up well (maybe a week or so), you can add a dry layer and slightly wash in. There is a fine line between too much and not enough. I am presuming these are rocks like river rock? This usually holds for years depending on usage. Regularly running lawn equipment and such over it can weaken it. May be lots of work but "but them there gets what them there does".

You could try paver sand. Its made to put in between pavers and then spray water and it locks then in place.