Yeah, you’re not wrong—once that sediment’s baked in, flushing only does so much. I’ve seen folks try all sorts of tricks, from vinegar to those “miracle” descalers, but honestly, sometimes you just end up with a bigger mess and a tank that still sounds like it’s making popcorn. That smell from vinegar can really linger too... not great if you’ve got tenants breathing it in.
I will say, though, if you catch it early enough, a good flush every year or so can buy you some time. But after a certain point, the buildup just gets too stubborn. I’ve had tanks where the noise was so loud it set off someone’s dog every morning—eventually, replacement was the only real fix. You did what you could. Sometimes, it’s just not worth fighting a losing battle with an old tank.