As a Singaporean I can assure you that becoming full authoritarian will not solve your corruption problem. China, Russia, North Korea for instance have wide spread corruption despite being far more authoritarian than us. The reason we have low corruption here is that society does not accept it and we pay our government officials (a bit too) decently. Punishments for corruption are stringent yes, but if you were to do a poll here people generally would agree with not accepting bribery. Essentially the punishment for being bribed is worse than the benefits one would get out of it. To put it in context the average indian police officer earns 33,561inr or an equivalent of 500 SGD vs 1780-2760 SGD for a junior police officer in singapore (this base pay ignores other allowances, sign on bonuses and scholarships given). Entry level inspectors can receive between $4000-$5000 (By comparison a junior SWE earns between $4000-$7000). The average Singaporean (or a relatively rich indian) can easily afford a one time bribe that is two times the salary of the indian police officer. I would have qualms bribing a Singaporean officer with two times his wage in singapore given that it would mean giving my whole months salary. Not to mention our punishments are much more severe if caught.
Rule by law countries use corruption charged as a way of getting rid of people they want to get rid of. If everyone is corrupt, then they all have that noose on their neck and so won’t step on toes they shouldn’t. Then the officials need only worry and get rid of those who aren’t corrupt (leading to a survival bias effect).