No, quite the opposite.
Take it with a grain of salt means check it; a million grains means check it a million times.
“Take it with a grain of salt”
Where I grew up in Indiana meant be very wary or even skeptical of what is being said.
Take it with a grain of salt means don't believe it or be skeptical.
Meaning:
1) to understand that something is not completely true or right
2) not take something too seriously
3) accept, but with some reservations or skepticism
4) don’t exactly believe something
(Source: theidioms.com)
Nothing about checking it.