"I'd love that.
"I think he would get a lot of satisfaction out of playing for Tonga."
Kefu suggested Folau could stay in the sport by taking his talents overseas before rugby's next showpiece event in four years, and The Daily Telegraph reports Forrests's Global Rapid Rugby competition may be interested in recruiting Folau.
Forrest started the breakaway league after the Western Force was cut from Super Rugby and according to The Daily Telegraph, as the competition expands next year there may be a place for Folau in teams based in Hong Kong, Singapore or the Pacific Islands.
Kefu said keeping fit by playing overseas — should he be dumped by RA — would be the best way for Folau to ensure he still has a chance of playing at the 2023 World Cup.
"He could definitely be available for the next World Cup," Kefu said. "He could still play top level rugby between those times.
"If he does get dismissed by Rugby Australia, he could play in top competitions like the Premiership in the UK or the Top 14 in France so there is still plenty of top level competition for him."
Kefu, who played 60 Tests for the Wallabies, said the Folau controversy has shone a light on how misunderstood the strength of Pacific Islanders' religious faith can be, and doesn't believe the former NRL and AFL star should face any punishment.
"I support Israel. I don't think anyone should be persecuted for something that he believes in," Kefu said.
"The debatable issue is whether he used the right platform. I think he should be able to make statements about what he believes in.
"I don't think he should be punished.
"No one should be persecuted for what they believe in and having the right to speak freely."
Kefu criticised Rugby Australia's handling of the situation for allowing it to keep "dragging on" and urged the governing body to bring a quick resolution to the matter.
"They need to kick this into touch as quickly as possible and move on," he said.