My iphone 6s button isn't working, i've tried cleaning it and it works for like 5 minutes and goes back to the way it was and how do i fixit?

My iphone 6s button isn't working, i've tried cleaning it and it works for like 5 minutes and goes back to the way it was and how do i fixit?

Clean it every sixth minute

Go to Settings>General>Accessibility>Assistive touch
This will give you an on screen home and lock button