We have a gecko. For the past 11 years. He (she?) has never really done anything that would lead me to believe his feet are magically sticky. Occasionally, he’ll stand up straight against a wall of his cage for awhile, but that is about it for “feats” with his feet.
Have you ever given him the chance? Try mounting pieces of plexiglass to the wall and ceiling of his cage. He might do tricks for you.
Both the green day geckos and the dark night guys do just fine on vertical surfaces and the ceiling. Only one we found with a problem is a baby we are raising that appears to have hatched prematurely and is not fully developed.