The command hooks we put near the shower are mounted on the metal frame for the shower door so that probably helps keep them there. We also put some on the luan siding near the vanity and they haven't come loose either.
We do clean the area with alcohol before applying the adhesive and make sure we hold in place with pressure for at least 30 seconds.
Note... the alcohol we use for cleaning is denatured or isopropyl/rubbing alcohol...we save the ethyl alcohol [liquor] ffor savoring after finishing up with the less tasty stuff