It is important to clean your fountain pens. It isn’t difficult or hard.
Note: there are some weird “only use sterile water” thingy in most fountain pen warranties. I have never followed this, but YMMW.
The way I clean my fountain pens is that a few times a year when I have written a pen dry I find a few glasses of room tempered water and get started.
For a piston filler I just move the piston up and down a bunch of times, until the water coming out of the pen is the same color as clean water.
The actual process of getting there is a little bit more to it than that. But I usually start with one glass and and do the first round to get out most of the ink.
Then I move over to a second glass and repeat the process a while more. When the water coming out of the pen is identical to the water in the glass I do a final fill and kind of rotate the pen for a while before emptying it. Sometimes it gets out some of the ink around the piston.
Then I do a symbolic rinsing in the third glass, but at this point it is typically more or less 100% clean.
For cartridge converter pens I take out the converter and find my syringes. Fill up the bulb and press water through the nib section two or three times.
And then I do the same with a ink syringe with the converter 4 or 5 times.
After all of that I find some tissue paper and put the nib to it to soak up as much water as possible, before I refill them.