That's kind of interesting, because it seems the product you've found effective didn't have the antimicrobial pine oil in it. I'd take a look at the ingredients and determine whether any could be the impact on reducing your mold growth. If it's a chemical agent, I might also want to be sure it is safe on all the surfaces it will touch, such as wiring, hoses and plastic, over time.
Your idea to experiment is good, however, they seem like short periods of time and very different weather circumstances. It doesn't seem like it would prove anything.
Good luck. Can't argue with success, however, you may not specifically realize what is causing the success and it may not be the evaporated cleaner at all.
There have been publications about the antimicrobial characteristics of pine oil. If you can tolerate the smell, it's probably effective. Whether genuine pine oil or a synthetic substitute, the ingredients are selected for their antimicrobial properties, and are sold by janitorial houses for applications where disinfecting are important. So it's not a stretch to suggest that making them airborne with a fan would have antimicrobial benefits, whether it's tea leaf oil, pine oil, or a synthetic substitute. I do think it's a bit of a stretch to worry about airborne pine oil touching surfaces through purely airborne transfer.
This looks like some interesting reading on a janitorial website: https://worldwidejanitor.com/library...s-of-pine-oil/
I'm not crazy about the smell of pine oil, so I'll probably just order a refill of the Kanberra gel which smells much more pleasant to me. Meanwhile, I just found an old tube of Paul Mitchell Tea Tree Styling Gel that a hairdresser friend gave me for Christmas a number of years ago. It has the same aroma as the Kanberra gel. I'm going to squirt some of that in a bowl while I wait for the order to come in.
By the way, there are lots of naturally occurring materials out there with antimicrobial properties. Under my dermatologist's direction I started using coal tar shampoo, which has done wonders to eradicate psoriasis in my scalp that had afflicted me for 20+ years. As of about 10 years ago, Ulladh was formulating his own bottom paint with coal tar (IIRC), though I'm not sure he's still using it now. I'm still impressed by Ulladh's practical knowledge of these things - don't dismiss them out of hand.