I’m wondering if there is a way to avoid the constant cleanings every six months. Has anyone used one of the special mouthwashes they sell on Amazon?
I heard some anecdotes regarding Periogen, but I could not find any studies in Pubmed.
Every 6 months is constant?? 
The scientific literature is pretty clear, even with regular flossing, rinsing, etc. healthy gums still require regular scraping of the plaque by a trained professional.
I’ve seen gum surgery up close, so I am diligent in my flossing and twice a year cleanings.
Dentist here. Good brushing and flossing are the key as well as limiting sugar intake to lessen plaque build up. Ask your dentist for a prescription for Peridex. It is a rinse that works OTC such as Glyoxide also helps as does dilute (50/50 with water) hydrogen peroxide. For my money Peridex is the way to go. It continues to kill bacteria long after rinsing. With extended use can sometimes lead to metallic taste and some staining or slightly increased tarter build up. If you are getting cleaning twice a year last two shouldn’t be a problem and I’ve never had a patient get taste issues. Can’t say about Periogen because I’ve never heard of it.