Cleaning habanero oils off of tools

You have a few options, including what should have worked. Capsaicin will dissolve in high-proof alcohol, so if you have a bottle of 151 you might have a go with that. Vinegar can also be used to dissolve the oils. These are probably more effort and expenditure than they're worth though.

You were on the right track; soap should have worked. In all likelihood, due to the concentration of the oils you simply did not wash it sufficiently. It requires quite a few passes (especially if the cutting board is porous) of hot, hot water and suds. As it is fat soluble you can try cleaning more thoroughly with most any soap with a de-greasing agent.

Moving forward, I have heard tell of spraying with non-stick spray to ward away the oils. I haven't felt some inordinate compulsion to do this and cannot attest to its efficacy, however with a slap chop and its nook and crannies you may find it a suitable use case.

Dilute bleach denatures the capsaicin nicely. Mix 1/4 cup bleach with 1 gallon water. Soak your equipment 5 minutes and rinse thoroughly. [insert "standard warnings on using bleach carefully" here].

Unfortunately, @mfg's suggestion of vinegar will not work any better on capsaicin than it would on a stain of vegetable oil. You need something that will either chemically alter the capsaicin molecules (something like bleach) or a strong surfactant (something like Murphy's Oil Soap). Rubbing alcohol is said to work as a surfactant, and I have heard it used on capsaicin, but I have not tried it.

If you're really concerned that your normal dish soap will not do a good enough job, capsaicin is extremely soluble in alcohol.

A quick bath in an alcohol and soap mixture (the higher proof, the better) will severely dilute the capsaicin and enable you to wash it away more thoroughly.

Also, the boiling point of capsaicin is listed as 410F(210C) so holding your utensils at this temperature for a while will cause it to boil off of the surface(although it will not disappear 100% in any reasonable time). It goes without saying, but do not put plastic objects in this type of environment and wood will not burn at this temperature, but will discolor after some time and probably be structurally unsound afterwards depending on the type of wood and the original moisture content thereof.

Experience tells me that it is not the utensil that is hard to clean, but the surface upon which you cut the produce. Dropping a plastic cutting board in the washer and hand cleaning the knife has never yielded problems for me. That said, I've cut chiles on my wooden countertop and then prepped a meal the next day only to find myself in tears after touching my eyeball.

I don't know how hot naga chiles are, but I've been growing and processing Carolina Reapers and Trinidad 7 pot chiles for a few years without issue.

Take great care if you try to can these chiles! The fumes are seriously dangerous!!!!

As someone who regularly uses very hot chillies, I have the following advice:

1. Use gloves (I don't, but I am told it helps. I use my hands, but wash them carefully).

2. Cut the chillies on a metallic surface: they are easier to clean; wooden chopping boards hold a residue.

3. Wash hands and all surfaces with vegetable oil first. The oil will be sticky (and, simultaneously, slick), so you have to do this patiently. Small amounts of oil are usually fine.

4. Wash the oil off with dishwashing liquid (you can use a drop or three of the liquid concentrate).

5. Finally, rinse your hands and all surfaces with water.

Surfactants rock where capsaicin removal is involved.
I used to make a very sharp, hot - habanero jelly for the select few around Xmas. I wore gloves to cut 1 kilo of habaneros that I grew in my backyard. After the jelly making was done, all my kitchen instruments were soaked in a dilute solution of vinegar. Once soaked, I ran out of the kitchen (the vapours can be a little strong too). Unfortunately the next day the nerves in my right fore-finger were on fire. My hand protection on the right hand, had a small hole in it. It turns out that habanero juice seeped into that hole...and marinated my finger the whole 4 hours I was chopping away at raw habaeneros. After a week of uncomfortable nerve irritation, I soaked my finger in vinegar...low and behold - relief! Holly

I have found that oil works well to get rid of chilli oil.

Use a little vegetable oil and rub in well, then use soap to remove all of the oil.

The logic is that the vegetable oil "picks up" and dilutes the chilli oils and also provides a much greater volume of oil that can be cleaned more easily. The soap contains surfactants that grab the vegetable oil and pull it away from the surface.

This also works on hands.