I had to look up the word 'kukui' and see it refers to the 'candlenut tree', whose nuts Hawaiians would burn to provide light... Nuts took 15 minutes to burn and gave its name to a unit of time...
Can you also use pani in this case? Wondering if this is where "shut the light" came from in pidgin ?
Not really because of the meanings of all the words. Pani to close or shut is to close up the hole of the door. Ho'opio means to extinguish like you extinguish a fire, because that is what ppl did with the fire of the kukui torch. To turn on the light, hoʻā, it is like you are igniting the light or the fire.