Thank you,
@K-2 !!!!!!
That is very mouthful one might say

.. for me you have already given here whole essence of ritual of how to hit the nail. Now I know all I am doing is wrong. I have about or more than 50 strait pen holders. They are all with a nib. (mostly with different nibs) they are part of the new nibs I find/ or buy as a lot then keep one on a holder for discovering a type of quality writing they give me. So that holder becomes a kind of permanent one for some times. I never use the same type of nibs on several holders. ( Yes unless there are ones refurbished from a Bach so I want to use first to save the best for later)
So none of these nibs removed cleaned and stored separately as you said. Now I understand I am compliantly wrong and I am suddenly scared and need to looking into all of those holders too.
This habit too is associated with my oblique pens of which I was talking about.
Now I understand I have to remove all those nibs and clean/dry and store in a box. I like using WD40/ I have a can, but never used it for storing but for cleaning some rusty nibs corrosions.
I'll consider using "mineral oil" and WD40.
So I have to think of leaving all the Oblique holders clean and free when storing. I have found many of my straight-holder's nib sections are rusty. Now I see the origin of the problem. They all need to keep dry and clean of ink and water.
Your point in using a ULTRASONIC BATH is a practical method to clean pens and parts of sophisticate items. I need to invest in a cheap machine too. ( Noted and thank you )
Thank you for all the details of Ink and types of inks and their effect to ware-out the nibs. I am at the time using my own home made walnut ink for my daily drills and practices . I learn that is the only ink keep the longevity of a nib better. I have many fountain pen inks too and I have also chosen just Sumi ink(Moon Palace ) as an alternative better writing.
I might use an iron gail ink and definitely use a cheap modern nib to work with that. I like to try that "Diamine Registry" one day and use Zibra / Nikko G or any modern nibs from my sample collections I have some where.
It is a good point again not to sand-cleaning the nib. I have a very worn-out Sandpaper and it barely feel sanding when I work on that. but I can see the rust is transferring onto the paper when you do it for long minutes. So I use Rubbing alcohol to clean the nib. that is how I do. As you say each nib has a technology of metal coating on every nib to have a smooth flowing of ink while it works on writing to generate a variable line according to the pressure ons use. So as for after sanding.. my writing, I don't feel any change of quality of my line width difference as all my writing are on Mono Line

at the time.
""
Maybe you'd be surprised by how many nibs active calligraphers go through when we're practicing or working often and regularly. I mean, there's a reason you can buy nibs by the gross (and ink by the barrel)...""
This is an area that we Newbees have never known or unseen. True and am I ready for that??? Before that I have many more other thought to tackle fight with.
Understand why we need to buy Nibs by Gross or lots and it has also mentioned in older hand books and manuals also.
Dear K-2 I, really value your long kind thought and loooooooog explanations. It is so kind of you to put that time to share your experience. I am sure this will be very headful for many as well.
Thank you and all My love joy and peace..