One tip from a rogue newbie TFPer that started out among pool expert friends and family: Don't say much at all. And let the water speak for itself after a year goes by.
Any time I explained TFPC the skepticism just increased. After a year of swimming, I "earned" two other family pools to care for because our water was noticeably clearer and nicer to swim in. Explaining TFPC got easier with the suspicion I had become a pool whisperer, haha.
Or you can always let a spouse or pool service do it for a year or two. Then you get to be the hero that fixes it with TFPC