Most DAWs have a number of included FX and saturation is often in the bunch. All this is essentially is a low level of distortion. Adding distortion creates the harmonics they mentioned in the ad.

You can find my music at:
www.herbhartley.com
Add nothing that adds nothing to the music.
You can make excuses or you can make progress but not both.

The magic you are looking for is in the work you are avoiding.