Quote - As Casper said "Walk paths are just for figures (characters)".  But you can cheat. Load a figure that is compatible with the Walk Designer, a lower res figure like the P3 Nude Man is preferable. Make a walk cycle for the figure, use a Run at 100% as this will give smoother motion. Now obviously if you parent a prop to the figures Body actor the prop will move with the figure.

The problem now is to hide the figure without hiding prop. If you were to select the figure's Body actor and set it to invisible, the prop would disappear as well. One option is to set all the parts to the figure to be invisible except 'Body', but this is time consuming unless you have a pose to do it for you.

A better alternative might be; apply the walk cycle to the figure, load a prop primitive, Set Figure Parent to be the primitive, yTran the primitive until the figure is out of sight below the ground, load your prop and parent it to the figures Body actor. Run the animation.

If you need to redo the walk cycle, restore the primitive to zero yTran first, then move it back down after applying the walk cycle.

An alternative to the above is to use ockham's "Hansel and Gretel" Python script to animate your prop:

http://ockhamsbungalow.com/Python/

Thanks for the Link.  Great Solutions. Great Python scripts. Thanks.
Hope this will resolve the problem.