Batons, billy clubs and blackjacks have a singular purpose.  Baseball bats, flashlights and walking sticks have a purpose other than inflicting pain and injury on human beings.

I think you'd have an easier time legally if you convert an object into a weapon of opportunity rather than carrying/possessing an object that was intended exclusively as a weapon.

The judge/jury/DA can interpret your intentions whichever way they wish.  The weapon you used may be a factor in that decision.

I'd personally stick with objects that aren't going to raise suspicion, and which don't resides in a legal gray area.

That's just my opinion. 

About 15 years ago my son-in-law used a baton and a stun gun to confront a Peeping Tom, the cops came and took the stun gun but gave him back the baton.  He struck the Peeping Tom with the baton, but the Peeping Tom ran away.  As usual, Hawaii laws are very vague, like stating any dangerous instrument. That leaves a lot of room for interpretation. They could say a Garden Hoe was a dangerous instrument if I struck somebody with it and seriously injured or killed that person.
Also a baton is not a blackjack, slug shot, or billy.

Deadly or dangerous weapon is defined as it's sole purpose is to cause bodily injury.  So a Krabat knife is defined as such.  But a knife who's product description says "utility" or camping, etc... is not deadly or dangerous.  Also a divers knife is not considered a dagger (sharp on 2 sides) or a dangerous weapon.  Knunchucks also is not defined as deadly or dangerous.

Most common is the Ka-Bar TDI knife.  But you can open carry it, even open carry a Samurai sword if you wish.

I guess in the end it's the LE that decides if he wants to bust you or not.  He could have arrested for the taser, but just chose to take it away instead.

About 15 years ago my son-in-law used a baton and a stun gun to confront a Peeping Tom, the cops came and took the stun gun but gave him back the baton.  He struck the Peeping Tom with the baton, but the Peeping Tom ran away.  As usual, Hawaii laws are very vague, like stating any dangerous instrument. That leaves a lot of room for interpretation. They could say a Garden Hoe was a dangerous instrument if I struck somebody with it and seriously injured or killed that person.
Also a baton is not a blackjack, slug shot, or billy.

You have to look at the case law/interpolation at the bottom of the HRS.

"Billy" as used in this section refers to "policeman s club" or "truncheon"; a club-like implement designed for purpose of striking or killing fish is not a "billy"; section extends only to weapons deadly or dangerous to people. 10 H. App. 404, 876 P.2d 1348.

Similarly, with "electric guns" HRS 134-16 notes that possession is illegal, including in the home. However, if you read the "definitions" section of HRS 134-1 one discovers that electric guns ("livestock prod") intended for animal use are exempted. They are for sale on ebay. Thus, theoretically, one could lawfully carry such an item openly or concealed in public.

§134-16 Restriction on possession, sale, gift, or delivery of electric guns.

Universal Citation: HI Rev Stat § 134-16
§134-16 Restriction on possession, sale, gift, or delivery of electric guns. (a) It shall be unlawful for any person, including a licensed manufacturer, licensed importer, or licensed dealer, to possess, offer for sale, hold for sale, sell, give, lend, or deliver any electric gun.
(This section goes on to list the lengthy exemptions for cops, etc....).

2011 Hawaii Code
DIVISION 1. GOVERNMENT
TITLE 10. PUBLIC SAFETY AND INTERNAL SECURITY
134. Firearms, Ammunition and Dangerous Weapons
§§134-1 to 18

§134-1 Definitions. As used in this chapter, unless the context indicates otherwise:

"Electric gun" means any portable device that is electrically operated to project a missile or electromotive force. It does not include any electric livestock prod used in animal husbandry and any automatic external defibrillator used in emergency medical situations.

what about a stun-gun, not a tazer,  that doesn't shoot a projectile?

what about a stun-gun, not a tazer,  that doesn't shoot a projectile?

Included as an "electric gun."

"Electric gun" means any portable device that is electrically operated to project a missile or electromotive force.
It does not include any electric livestock prod used in animal husbandry and any automatic external defibrillator
used in emergency medical situations.

what about a stun-gun, not a tazer,  that doesn't shoot a projectile?

I don't know but they hurt like hell and definitely piss people off.
ZZZZZTTTTT! 

PIZZA !

I love pizza!