West Ham finished seventh last term but have struggled since moving to the London Stadium at the start of the season, winning just five of 17 league games so far.
"There is nothing wrong with having a couple of beers at the right time, after the game," Bilic told the British media.
"I want (the players) to be mentally free, I want them to enjoy their lives. I want them to enjoy that we had six points from these two demanding games."
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Away from the London Stadium, the team have picked up five points on their travels and Bilic said that unlike his players, he would spend his time preparing for a tough run of fixtures.
After the Swansea game, West Ham travel to champions Leicester City on Dec. 31 before hosting Manchester United on Jan. 2.
"I (will) take my staff out but I told them, 'No Christmas party,'" Bilic said. "We can have a Christmas party in January or February, let's do the business first, because I want to enjoy that night out."
(Reporting by Hardik Vyas in Bengaluru)
