Talk show host and political comedian John Oliver dedicated a full segment of his HBO show “Last Week Tonight” to tearing down Donald Trump’s campaign promise to build a border wall between the U.S. and Mexico.

Oliver Calls Wall a Big, Dumb, Expensive Idea

The 38-year-old English satirist reminded his audience that Trump has estimated the cost for the proposed wall to be anywhere from $4 billion to $12 billion. Oliver said that the real cost is actually closer to $25 billion, and that number does not even take into account the maintenance costs, which the Congressional Budget Office has estimated would exceed the initial construction costs within seven years.

“So it’s a big, dumb thing that only gets more expensive over time,” said Oliver.

The host pointed out that, although Trump claims he will make Mexico pay for the wall’s construction, there is no evidence that the country will do this, and Mexican officials have expressed their total opposition to the idea.

Oliver played a clip of former Mexican President Vicente Fox using an expletive to emphasize that he would not pay for the wall. Oliver praised Fox’s choice to curse in English.

“I think the best part of that clip is the fact that he even took the extra effort to swear in English,” the comedian said.

An Inconvenient Treaty

Oliver explained that the planned wall would logically be built along the Rio Grande River in Texas, but a 1970 treaty ensures that no construction can obstruct the flow of the river.

This is already a problem for existing sections of the barrier. Because of this treaty, large areas of the border fence approved in 2006 have been built inland, resulting in a logistical nightmare for Brownsville, Texas, where a golf course was stuck in a kind of no man’s land between the border fence and Mexico.

The fence has also led much privately owned land to be claimed by the government via eminent domain.

Waffles Instead of a Wall

Since Trump’s idea for a border wall seems to be all about making people feel good, Oliver suggested that a cheaper and just as effective gesture would be to buy a $75 electric waffle iron for every American.

“If the main thing it’s going to get us is a warm sense of satisfaction inside, I suggest instead of building that wall, we use the money to buy every man, woman and child in America a Palmer Waffle Iron," said Oliver.

Since the waffle irons retail at just $75 apiece, Oliver reasoned that the U.S. would still have almost $1 billion left over.

"This waffle iron plan will cost less, will do nearly as much to keep out immigrants and drugs, and it won’t harm our relationship with our third-largest trading partner. If it is racist, it’s only toward Belgians,” joked Oliver.

Their Latest Feud

Last year Trump and Oliver engaged in a Twitter war. The candidate claimed that, although he had been asked many times to go on Oliver’s show, he would not waste his time or energy to do so. Oliver was adamant that he had never invited Trump to be a guest.

On CBS' "This Morning," the comedian elaborated on his disinterest in interviewing Trump.

“I’ve really got nothing to say to him,” said Oliver. “He’s said everything he wants to say. He’s got no internal monologue, that man. It’s not like you’re going in to find the secret nugget he’s been holding back.”