It comes after a man was arrested for smashing a window at Foreign Minister Winston Peters' house during a protest on Monday.
Appearing on Morning Report's weekly political panel on Wednesday, Willis said, rather than policing language, people should take a stand on bad behaviour by protesters.
"I think we shouldn't be so precious that we can't use metaphorical speech and political speech," Willis said.
"[Greens co-leader] Chlöe Swarbrick wants to police language. What she refuses to take a stance on is those protesters protesting outside private homes disturbing neighbours, family members, people's pets and that is serious and in my view she should be taking a stance on that."
Willis on Tuesday urged the Greens to "call off the dogs", referring to protesters who have been outside Peters' home multiple times since the New Zealand government's decision to not recognise a Palestinian state yet.
Willis told Morning Report the phrase often cropped up in politics and dated back to the time of William Shakespeare, who referred to calling off the hounds in his play Julius Caesar.
She believed Swarbrick had a great opportunity to calm things down over the Gaza situation and tell protesters they had gone too far.
The Greens have condemned the attack, while also criticising Willis' rhetoric and calling on government ministers to "look in the mirror".
Swarbrick said the protests outside Peters' home were "entirely legal", though she stressed she had not been involved "in any way, shape or form" in organising them.
"We have had absolutely nothing to do with that."
Swarbrick defended hosting a press conference at which 'O'Connor appeared, saying she could not be expected to know "absolutely everything about everybody" she stood next to.
Also appearing on the political panel, Labour's Megan Woods said all political violence was unacceptable.
Labour had opposed the law change making it illegal to protest outside politicians' homes in part because the definition of a home wasn't practical.
She used the example of a home in an apartment block with commercial premises, and said laws already covered what happened outside Peters' property.
Willis countered, claiming Woods' position was "weasel words". If the law change was supported in principle any "technical issues" could have been worked through at the select committee stage, Willis said.
Woods said Labour's concerns wouldn't have been eased at the select committee.
"We do have to be very careful that we're not putting in place protections that do override the right of people to have peaceful protest, and I do emphasise peaceful."
