This is a very informative video!
I have a book from 1933 called "Draw Comics! -Here's How-"; That book also tells you how to prepare a new nib. It says to hold the nib under a match flame for a few seconds, Then gently rub it against a sharpening stone. My, how times have changed!

Am so high that a thought it was three joints 😂😂

Thank you! I just got a dip pen set as a gift, and only ONE of the nibs worked. There seemed to be plenty of ink in the reservoirs of the other nibs, but it just wasn't flowing. This video is one of the first ones that popped up when I tried to figure out what was wrong, and your tips solved the problem! 😁

I would think rubbing alcohol and a microfiber cloth would cut the oil off. I have a few nice knives to which I apply mineral oil to prevent rust blooms. I clean them with rubbing alcohol & microfiber cleaning cloth for sharpening or stropping. Many knife companies include them with pricier knives.

I just got started playing with my new dip pen. Now I know why it's been so stubborn 😂😂😂

Fine sandpaper works well for me , strokes along the length consistently- I get phenomenal results

And here I am thinking I do something wrong when it works poorly, must try to clean my nibs. Thanks a lot!

A good little experiment, always helpful to compare techniques.
Pen companies themselves should know the best way to remove the coating they put on. I have always used a toothbrush, ordinary bath soap and the tap. Way back 25 or so years ago I used a flame but had no idea how long to do it for at first. I found out later you should re-temper the nib with an immediate dip in cold water. You only take  the nib back and forth over the flame about 2-4 times once per second or so. Make sure you catch from the tip to the far end of the reservoir (the elongated hole) and do both upper and lower surfaces. So it should take no more than around 6-8 seconds in all before you dip it in the water. Don't linger over the flame; keep it moving.
As you only dip deep enough to flood the reservoir there's no need to clean it much past there. Always use a well deep enough that when you dip, the reservoir hole is submerged and comes out with a thin film of ink - then it is full. I noticed you weren't doing that.

Acetone and spit has worked better for me than window cleaner, oddly.
But I've never tired boiling water, I'll make sure to try it some time :)

Tried acetone and a flame before getting frustrated and searching YouTube.
Glad I found your video... Boiling water did the job! Many thanks.

Many people recommend heating the nib with a flame but hitting the nib with a flame is one of the most idiotic things you can do to it. Nibs are made from spring steel, which contains between 0,5-1% carbon, so it can be hardened. That´s importtant because a nib made from mild steel would just bend and not spring back into it´s original form. To achieve that, nibs have to be heat treated. The first step is to heat the steel to around 800°C and then cooling it off quickly, for example by dropping it in oil. The steel is now very hard but very brittle. The nib would just break. That´s why there is a second step to the heat treating process, the tempering. The metal is heated up again, usually to 200-300°C, depending on the properties the final product is supposed to have. The tempering takes away a bit of the hardness but gives the steel it´s flexibility back. In order to burn off the oil from the surface you would have to get the nib way hotter than 300°C. That means the nib would be much softer than the manufacturer intended. It would not be as springy as before and it would wear out much faster. It´s a good way to ruin a nib.
Boiling water on the other hand is fine because it´s only 100°C

T-h-a-n-k  you!  Stopped trying to use my nibs because they-didn't-work !   Now I will try these methods.

I use toothpaste and an old toothbrush, also in addition, get the edge of a piece of notebook paper between the tines a few times to help clean between them.

I use tooth past with a tooth brush. It works great.

Thank you so much Liz for this very helpful video!

Great video and super helpful! Thanks so much! :')

Thank you -- this was VERY helpful.  I've dabbled with dip nibs on and off, and have often had trouble making one write well.  I was aware that they were said to be coated with oil, wax, or shellac, but I had mistakenly convinced myself that if no coating was visible, then I didn't need to worry about it.  When ink wouldn't cling to the nib, I blamed it on the ink being too watery or not tenacious/viscous enough.  After seeing your video (and others on this topic, though yours was the first one I came across 😉), I've started cleaning some of the vintage nibs I've collected over the years, and the results have been fantastic.

You started your video by saying these were things you wish you had known when you were first getting started.  I would add this - even if you can't detect a coating (and it appears that one usually can't, even on new-old-stock nibs that are decades old), you should assume it is there, and go ahead and clean or prep the nib.  It's not that much effort, and if nothing else, you will have eliminated one possible source of trouble.

thank you so much for this video. Very informative

Thank you, ma'am, for the great explanation. (I had not understood the problem that oil or wax caused in the other videos I saw.) Also, thanks to all the commentators for the tips :)

Fantastic, thanks! (I followed your advice to use boiling water)

I was taught to use liquid ammonia diluted with water, which is one of the ingredients of the glass cleaner.