Keep in mind that in a commercial movie/video the studio may have spent a huge budget and thousands of man hours creating such an effect. To be able to duplicate it in a $100 program is often not reasonable.
Do you have a video clip of a wave washing up on the beach? You could create title screens of the names and use something like the "bump" track composite function (does Movie Studio have that now?) to make it look like the name is written in the sand, then transition to a duplicate wave clip using a wipe timed to the wave to make it disappear. May not be the most believable effect, but it would be a starting point.
Then there's also actually writing the names in real sand and using the wipe transition to a clip of smooth sand as mentioned above.