Somebody needs to get this guy a “minder” with some business sense as well as a sense of probity, partner them up, set up a GoFundMe page and go to it, I think he really could make lemonade out of this lemon of idiocy. Depending, of course, upon just how desirable the homebrew might be, I have no idea what New Zealand prison homebrew consists of, or what it tastes like. Making hooch shelf-stable might be a challenge too, but surmountable I’m sure.
Where there's a profit to be made, there's a way.
On the downside, the government would probably resist commercializing a down-market competitor to their highly-regarded wine industry. Anoreth and I have a bet on future geopolitical events, and I've suggested a wine trip to New Zealand as a possible stake.