The dirt idea bugged me -- especially the toenails -- until I did it the first time and saw how everything comes off cleanly and leaves no grunge behind. :)
I don't eat any of the giblets, but I always put the liver, the heart, the gizzard, and the testicles into my soup stock along with the feet, the neck, and the backs,
Glad it worked for you.
IMO, getting the strength of the pull just right so that the neck is dislocated at the first pull but the head doesn't come off is the trickiest part.
Thorough washing with clean water should do the job in re: gut contents. Probably ends up cleaner than...