I think that glass tube really spreads it out more than fix it.
I like covering a pot of water with foil poking a whole in the foil, and boiling the water. Fix the dent by directing the steam coming from the hole at the dent.
You can also use a shot glass or the edge of a Bic lighter. But that is correct, it only spreads it out.
In the linked video, the person put a pretty healthy dent in the shaft. I doubt that any amount of rubbing would take that one out completely.
Some people have a Steam Gun in their home for other types of cleaning. If you have one, that works 100%.
If not, the improvised steam gum with tin foil works great.
I would suggest that you try a Wet Bandage first.
Take a paper towel, fold it several times until fairly thick. Cut a small square from one corner.
Wet the square and squeeze out a bit of excess water. You don't need it sopping wet but a little water is what you want.
Place wet bandage over the ding. Give it 20 minutes or so. Check and see if the ding is gone. If not, re wet and wait again.
If the fix evens out great. If the water has caused the wood grain to raise a bit, use a fine grit sand paper to sand to level.
Seal or wax and polish.
Depending on the depth or severity of the ding, the bandage and or steam will work pretty much 100% of the time.
If the ding is deep and severe, they can be filled in with a little CA Glue and sanded to match the shaft. Whether you want to try this yourself is up to you.
Easier to add a bit of glue, wait till it dries and add a bit more. Rather than put a huge dob on right away and find that you have more sanding to do than you need.
If you have a Laminated Shaft, do not use Steam on it.
Heat or in the form of Steam is Glues worst enemy.
And obviously, the splices in Laminated Shafts are glued.