SeaFoam has come up on the Jukebox here, before...
No arm wrestle: if you like it/works for you, good.
Some other views and opins on using that product in modern engines pasted below, but maybe your diesel is different or more receptive.
GL, mD
Post #7, and others in this thread:
http://www.xoutpost.com/bmw-sav-foru...additives.html
http://www.xoutpost.com/bmw-sav-foru...v-seafoam.html
http://www.xoutpost.com/bmw-sav-foru...4-engines.html