If you go walking around carrying weapons, it can be easily argued that you went around looking for trouble if trouble happens. If police catch you with a weapon, you're in a great deal of trouble innocent or not.
To me the sad reality of self-defense in Hawaii comes down to plausable deniability that the item you use was ever intended for use as a weapon, and rather it is used impromptu for self-defense. For example:
I have my keys on a large metal carabener (those D-rings that mountain climbers use). This is a common way to carry keys since it can easily be attached and detached from a belt or belt loop. In a pinch my fist fits nicely into it and can be used as makeshift brass knuckles. It doesn't look like a weapon, in no way is it considered a weapon until it is used it as a weapon.
Some guys carry a baesball bat in the trunk of their car. To me unless you're a baseball player, this is an obvious weapon. Instead I carry a 4D battery maglite. If a police officer pulls me over and sees a maglite in my car, he's not going to question it. It's a flashlight first and foremost. However if a bad situation arises, I have a sturdy piece of metal piping that can be used in self defense.
I like blunt weapons over blades because whenever you use a knife or a blade, it spills blood. Juries can be easily influenced by emotions and shock value. A picture of a would-be-attacker with his own blood stained down the front of his white T-shirt is going to get a much more sympathetic knee-jerk-reaction than that same attacker bruised up with a broken jaw and a broken collar bone.
The rest of my self-defense comes down to being mindful of my surroundings and never putting myself into a situation I cannot either flee from or fight my way out of.