What would be the most effective remedy for cure gum disease?

No cure, sorry. It is a chronic disease, which we can make better and manage, but it usually doesn't go away forever. The only known "cure" is to pull out the involved teeth, but please don't do that if at all possible.
Good oral hygiene. The most important aspect of gum disease prevention, treatment, and maintenance is home care oral hygiene (brushing and flossing). If we don't have good home care, we will fail at prevention, treatment, and maintenance.