No it is not. It will be not very effective.
Proof: https://replay.pokemonshowdown.com/gen8ou-1191801178
No, it's not. Rock resists Drill Peck.
Source: experience.
Drill Peck is not super-effective on rock types. According to this site's data on the move, "Drill Peck deals damage with no additional effect, besides being able to hit non-adjacent Pokémon in triple battles.". https://pokemondb.net/move/drill-peck
Irrelevant, but Drill Run is super-effective against Rock types because it is a Ground type move. https://pokemondb.net/move/drill-run
Hope this helped! :D