Two Dunedin secondary schools cancelled the after-parties and more look set to follow because of fears they are against the law.
Pupils pay to attend the parties, which are highly controlled and until recently had the support of police.
A recent North Island district court decision has changed the interpretation of the Sale and Supply of Alcohol Act, largely because the parties are usually ticketed.
David More said his solution was for parents and pupils to set up a social club for the purpose of organising the party.
Pupils would pay a small membership fee, which would pay for the event.
They would need written consent from a parent or caregiver to join.
"The [social club] puts on a private function and the members are admitted free.''
The club would not need to be incorporated or legally registered.
"Somebody could run off a set of rules in about five minutes flat.''
Mr More believed police were wrong to discourage the parties.
"It's very ill-judged on the part of the police to raise this issue. They should be turning a blind eye to it, as they do to many things.
"Why are the police singling out properly run functions?''
This week, Columba College pupil Jenna Chisholm (18) and her mother, Jill, spoke out in the Otago Daily Times about the cancellation of the college's after-party with just a few days' notice.
Mrs Chisholm feared the crackdown would lead to pupils organising their own parties, which would open a "can of worms''.
Asked to respond, a police spokeswoman in Wellington released a statement that did not address Mr More's suggestion.
"Police have no problem with after-ball parties, provided they are run within the law.
"It is the responsibility of parents/party organisers to ensure a safe environment around alcohol, and model appropriate behaviour for teens, while those young people who are at the legal age to drink need to be responsible for managing their own alcohol consumption.
"While police want young people to enjoy their after-ball party, we want them to do [so] safely without the risk of harming themselves or others.
"Police will continue to work with schools in an effort to prevent and reduce alcohol-related harm and we ask students, parents and party organisers to take care,'' the statement said.
