Take it like a grain of salt?

To take with a grain of salt means to accept but to be still skeptical about something.

To take take salt out of salt water you have to boil it, then refrigerate it till its the right temperature to drink.

You can take out salt out of salt water in a process called distillation.

(You) is the understood subject of the sentence. The adverbial phrase is "what she says with a grain of salt." Try replacing the words that seem to modify the verb (which is what an adverb does) with...

Crystal is quartz that is almost transparent. Describing a snow flake or a salt grain as crystal would be a fair description.