The best way to clean drainage depends on the type and severity of the clog. For minor clogs, using a plunger or a drain snake can be effective. Chemical drain cleaners may also be used, but they can damage pipes and should be used sparingly. For severe or recurring clogs, it's best to hire a professional plumber who can use specialized tools and techniques to clear the blockage safely and effectively. Regular preventive maintenance, such as flushing drains with hot water or a vinegar solution, can also help prevent clogs from forming in the first place.