In-game it is not a bad choice, but competitively it is a different story.
Competitively, no way. Being immobile for one turn leaves you vulnerable and you will normally get OHKOed, or set up on by dangerous sweeper such as Gyarados. Trust me, Fang does NOT want to take Focus Blast or even a Close Combat after the defense boost, Sharpedos have mediocre defenses and can barely take any neutral damage STAB. So, no do not teach it Skull Bash.