Pepper spray gets carried quite a bit around here, but not by me. With respect to pepper spray, wind is not your friend, and around here the wind doesn't blow, it sucks. If I lived in an area where heavy bush was the norm, and the wind wasn't, perhaps I'd have another point of view, although being a gun guy, I doubt it.
If you are determined to use less lethal bear deterrents, cracker shells fired from starter pistols or shotguns are the primary line of defense, followed by or in combination with rubber bullets. There are implicit dangers with the use of cracker shells. First there is the chance of putting the cracker on the wrong side of the bear, with the predictable results. That bear will very rapidly close the distance between you, so you'd better have a plan B ready to go. The second problem is that when used in a shotgun, cracker shells can leave partial barrel obstructions, so it you have to follow up with live fire, you're somewhere between a train wreck and a rodeo. For this reason my preference is to have a scare gun and a killing gun, and two man teams. If working alone, the best solution is to carry a lethal long gun and a scare pistol. In dry country a cracker shell can start a grass fire pretty quickly, so particularly when practicing with them, be aware of this.
It is possible to seriously injure a bear with either a rubber bullet or a cracker shell, particularly if they are hit at close range. The rubber bullet will split the skin, or break a rib. At least once here, a bear was hit in the ribs with a cracker shell at bad breath range, the cracker penetrated the ribs, exploded inside, killing the bear.
Modern camps frequently use electric fences to keep unwanted wildlife away from grub and property. Beware though, if a bear, particularly a big bear, is hungry, and he can smell food, he'll go through the fence. When he does, not only will he be hungry, but he'll be grouchy too. Now you are inside a small fenced compound with a hungry, hurt, grouchy bear. The rule here is to be smart with your food storage and cooking.
If you find yourself in a dangerous bear situation, your brain is your best weapon, keep it loaded.
Here we see a cracker shell fired from a shotgun passing the bear
12 ga rubber bullets
A bear that was injured by a rubber bullet that was fired at too close a range that hit bone rather than muscle
Some situations can only be handled with lethal fire