Yeah. I have done that a few times on the advice of a friend many years ago. It does help a lot to come up with phrasing. And, on more complex melody helps to nail pitch. Not really being a singer, even with this trick, finding pitch is hit or miss.

Or a memory problem.
One take off from that, that's worked for me, is when I'm starting to get serious with a lyric idea I'll be playing guitar chords and hammering and pulling and trying to find some chordal melody, leading tones, and so on, and putting my lyric ideas to that. Found some hooks, new lyrics, arrangements, and groovy riffs that way. In the end the lyric seems to meld with the tonal structure of the song. Both music and words flow better. I listen for the rythym, or my strum pattern and the phrasing seems to flow off that specific timing. This is all just my own subjective experience and it's always fun trying.
Sometimes though you just can't fit that word in and have to work on syllabic content. Or worse. The dreaded shelf.
Have fun with it Guitarman
Bruce