Mini nail polish machine to smooth PLA?

[SkyKisser]

Hi
I am trying to find away to smooth PLA model after print. I have tried sand paper and it works well, maybe too well that it scratch off some color from the surface which makes it does not look very nice.
My wife suggested me trying out this little machine but I am not sure.
Do you guys think it will work better than sand paper and will not scratch off the color?
I really can use some advices. Thanks alot guys.