(CNN) "Drain the swamp" was a refrain of Donald Trump during the presidential campaign, but on Wednesday Newt Gingrich said the president-elect "doesn't want to use it anymore" now that he's knee-deep in alligators. Trump tweeted Thursday that he will "always be trying to (drain the swamp)."

"I'm told he now just disclaims that. He now says it was cute, but he doesn't want to use it anymore," Gingrich, who informally advises Trump, said Wednesday on NPR's "Morning Edition."

The former House Speaker said that he had "written what I thought was a very cute tweet about 'the alligators are complaining,' " but that "somebody wrote back and said they were tired of hearing this stuff."

Trump corrected him on Thursday.

"Someone incorrectly stated that the phrase "DRAIN THE SWAMP" was no longer being used by me. Actually, we will always be trying to DTS," he tweeted.

Someone incorrectly stated that the phrase "DRAIN THE SWAMP" was no longer being used by me. Actually, we will always be trying to DTS.

Gingrich quickly admitted he "goofed" after Trump's tweet.

"I goofed. Draining the swamp is in, @realDonaldTrump is going to do it, and the alligators should be worried," he tweeted.

I goofed. Draining the swamp is in, @realDonaldTrump is going to do it, and the alligators should be worried. #DTS https://t.co/nCHs61gpve pic.twitter.com/OCO7eaSKvk — Newt Gingrich (@newtgingrich) December 22, 2016

During his campaign, Trump repeatedly vowed to "drain the swamp" -- leading chants of the phrase at his rallies -- part of an anti-establishment, anti-Washington message that was predicated on rooting out corruption and bringing an outsider's perspective to government.

But since the election, the phrase has been turned against Trump with biting irony.

Critics have used it to assail Trump's high-level appointments of Wall Street and DC veterans, like former Goldman Sachs executive Steven Mnuchin as treasury secretary and Sen. Jeff Sessions as attorney general. Ron Klain, a former Obama administration official, tweeted, "Sure, Drain the Swamp. Congrats to all you outsiders who thought that Hillary Clinton was too establishment."

Sure, Drain the Swamp. Congrats to all you outsiders who thought that Hillary Clinton was too establishment. https://t.co/T2c9eQmeEZ — Ronald Klain (@RonaldKlain) December 20, 2016

Gingrich on Wednesday explained away the gap between Trump's rhetoric and actions, saying that "he's in a different role now, and maybe he feels that as the next president of the United States that he should be marginally more dignified than talking about alligators in swamps" -- a euphemism for the kind of establishment insiders Trump vowed to expel.

"I personally have a sense of humor, like the alligator and swamp language," Gingrich said. "I think it vividly illustrates the problem, because all the people in this city who are alligators are going to hate the swamp being drained. And there's going to be constant fighting over it."

Trump has in the past expressed mixed views on the "drain the swamp" line. At a rally in Ohio in late October, he explained that he hadn't liked the expression at first, but that it had grown on him.

"We are going to drain the swamp. You know, that phrase started about a week ago, and I thought it was terrible. I didn't like it at all. I said I don't know; I just don't like it. And now it's become one of the hottest phrases anywhere in the world and I'm saying I like it," Trump said at the time.

"That's like -- did you ever see the great singers, Frank Sinatra, some of his greatest hits he didn't like them. But at the end he liked them very much. Right? It's what happened with drain the swamp. It's a great phrase. But it's true. The people like it. That's much more important."