What kind of infection did you have (outer, middle, or inner ear), and what kind of antibiotics were you taking (oral and/or ear drops). How long ago did you finish the antibiotics?
When you mention mucus, typically that refers to middle ear congestion so Debrox will not help. Debrox is for softening ear wax and ototic debris in the external ear canal.
If you have a perforation of your eardrum, the mucus and pus can drain from the ear. If you have a discharge from the ear, you shouldn’t put anything in your ear unless it has been prescribed for you following an examination.
If you have middle ear congestion, decongestants such as Sudafed (available at the pharmacy counter without a prescription) can be helpful although some studies have suggested that it actually does not help, especially for those with chronic middle ear infections. Mucinex (guaifenisen) may also help loosen the mucus to aid in drainage.
You may want to find a local walk-in clinic for an examination if you are unable to see your family Dr. or ENT. This is especially important if you have any pain or fever that might suggest a recurrence of the infection.
FYI- I’m an audiologist.