I've never had any paste on any of my seat posts from the LBS.
I found my seat post did almost seize eventually in my Madone, I applied carbon paste, but it still needs checking every 2 or 3 months as it does start to seize again. On my other Trek, I applied Molycote grease to the seat post after it seized, and I never have a problem. When I get round to it, I'll stick Molycote on the Madone.
Ordinary grease is not supposed to be applied to carbon seat posts as it weakens them. Bontrager on their website used to advertise that their seat posts are not affected by ordinary grease. Its a case of searching online, and making up your own mind, whether too or not use ordinary grease