This is the box I made. I've made a few modifications since, like a perspex window in the front, lined it with foil for reflectivity, and connected it to a HEPA filtration system, but I'm using it for purposes other than cleaning apples
There are lots of tests being carried out on the efficacy of Ozone and UV/Ozone combinations for sterilising N95 masks and CPAP equipment, and the results are promising. E.g.
https://www.medrxiv.org/content/10.1101/2020.05.28.20097402v1.full.pdf
... but I wouldn't endorse it,
For anyone thinking of building anything similar, please remember that UV light is very bad. Treat it like a wasp. Don't let it near your skin or eyes. Plastics make excellent UV blockers.
High concentrations of Ozone are also bad for you, so ensure good ventilation during use, and before you use any power tools, be sure to ask a responsible adult.
There's also electricity involved. Electricity is bad.
Probably best to just not even think about doing anything like this.