Hello Sir,
I would suggest that, prolong use of mouthwash is harmful to the oral health like...... causing staining of teeth & other side effects.
But,
If you are suffering from any oral health issue get consultation with dentist & then use the medicines for the prescribed period only.
Next Steps
get consultation with dentist either online through Practo or offline by in person visit to the dentist.
Health Tips
maintain oral hygiene by following proper oral hygiene instructions as advised along with that you can rinse mouth with lukewarm salt water after every meals .
Also,
please don't self medicate!
Thanks!