Cleaning your PS4

Where you need to press eject and another thing at the same time.

I had a feeling about the answer but I preferred to make sure

but it's not at all for cleaning, it's to control the fans
and another case where it is used to eject a CD in case of failure (YLOD)

https://www.commentcamarche.net/faq/23833-comment-ejecter-un-jeu-ps3-apres-une-defaillance

has nothing to do with cleaning a PS3
it's actually the best way to fry it, which is why Sony strongly advises against it

you use a can of compressed air or a vacuum cleaner on the vents

No, it's really to clean it and Sony advises that your console lasts longer...