How to avoid self-transparency artifacts?

Questions
1

when set material to transperant，model will show like below:
image
Does anyone know why?

2

Issues like this were discussed in the past multiple times for example:

Both threads provide workarounds in order to avoid or mitigate self-transparency artifacts.

3

thanks for replying!
I tried all the solution that Mentioned in these threads , but still cannot avoid the self-transparency artifacts when the model has two or more layers in one mesh , like the urinal model above.