What does a cleaner do?
A cleaner is to make a scanned page Black & White in grayscale mode. S/he will remove all Japanese/Chinese/Korean text. Sound effects aren’t mandatory for some groups. Basically they are beautifying and fine-tuning the manga page. Cleaners can also be re-drawer in many instances. There is a sub-position for cleaners, which is re-drawer. Some cleaners can’t re-draw at all and that is why this position is made.
-Resize the image(if instructed)
-Remove all foreign text that are relevant to the series
-Remove SFX where it’s possible for cleaning(try first)
-Level(and curve) the page
-Grayscale the image
-Use denoise(not mandatory)
Or just check the #cleaning101 tag