What does āconditionsā really mean, I wonder?
I have no illusion that any kind of hardening will prevent tearing skin or bleeding as you strike hard.
What I observe is that those that claim to work the bag without gloves
1) They minimze contact time and avoid strikes that imply that your hands slides or drag the bag. The latter will tear skin.
The safest strikes that work fine without gloves are clean purely perpendicular strikes without lateral force compoments. So getting into the habit of using ONLY these seems to be the trick.
But I think that excludes too many nice strikes, so i use gloves to train all kinds. In a right fight i would not care about ripping skin, it's not worse than a bruise, it goes away fast.
My personal experience is feel that generally conditioning also of other body parts mainly means
1) mental conditioning, such as enduring benign pain, and not letting pain distract your focus of the opponent, is the main benefit. Learning to distinguish dangeours from benign pain, and dont let benign pain take your focus away.
2) Some other conditioning seems to be about learning microsdjustments in posture and alignment and internal synchronisation and neuromuscular improvement at the instant you deliver and eating strikes.
I think these things are more important than the physical conditioning, such as growing thicker skins or bones, killing sensory neurons, or whatever people imagine.
Neuromuscular part and mental pain conditioning takes you a long way I think. Neuromuscular training when hitting seems to be also about the exact timing when impact comes and when to peak. This is easier to learn IMO when you have a more distinct target. A too swampy bag or no bag at all, or too swampy boxing gloves, you dont get the precise feedback you need to learn. This is how i feel at least.
OTOH if you hit the bad purely for cardio training, then the purpose isnt to perfect all the techniques anyway.