First thing to understand is why chaffing occurs? main reasons are friction and infection. Both occur due to sweating. Then logic says that the best ways to avoid chafing is to reduce sweating. You want to stay cool. But it seems most people prefer tight fitting boxer briefs which infact cause more sweating. Personally, what has worked for me is no underwear and wearing thin, light, breathable pants. Regular washing means ZERO chafing. Just going commando on your next hike may not help. You may need to adopt this as a lifestyle.
Keep in mind that all the sweating that accumulates in your underwear causes it to stink. And no underwear means one less thing in your gearlist.
