I pull the piece with the swinging top with the gasket out of the way, spray the inside with my vinator 3-4 times, then on my very last squirt, in one fluid motion, I let go of the swinging cap and dip the bottle mouth into the bowl of the vinator and hold it under for a couple seconds to soak the top, the mouth of the bottle and the gasket,.
In one fluid motion without breaking stride in my sanitization process.
Just "Squirt squirt squirt dunk dunk drain."
Easy peasy.....
And if you are bucket sanitizing, when you are dunking the bottles in, you are also letting the ceramic and gasket soak in sanitizer as well.
That's all it really takes.
(but you probaly don't even need to bother with the dunking step, because, since you have inverted the bottle to drain it, more than likely the gasket/ceramic top, will swing back under the mouth of the bottle and will get sanitized by the liquid falling out of the bottle as you drain it.
FYI O wouldn't boil the gaskets, the heat will warp them and weaken them, especially with repeated use...that may lead to eventual gasket fail, and un carbed bottles. Me personally, if I bothered to remove them, which I rarely do, I would just soak them like I do my caps in the bowl of the vinator with sanitizer..or in a seperate little bowl.