I have these stains on the toilet glass corners and washing bowl's area, I have tried brush and normal cleaners but they won't come off. Can someone recommend ways to clean up them?

bottom and top picture stain at silicone joint?

easy way is to scrap out and re apply

for sink and floor can try lemon juice + baking soda (can google this method)

or try Mr Muscle brand marble cleaner (big bottle around rm20)

this marble cleaner very powerful even one of my contractor using this to clean and polish marble but i can't guarantee coz he using machines and maybe different methods

The bottom and top are not silicone, there seems some kind of plastic material that covers the line.

Lemon juice + baking soda, sounds too much trouble and maybe not effective enough. will look for Mr. Muscle marble cleaner.
Is it common to look for special cleaning service to do this kind of job? if yes, how to look for those services?

that is clear silicone

same material at vertical joints rite?

u might want to Google for that method reviews and videos

it really works like magic

i lost contact for specialist

Dr. Bath,

any problems regarding toilet he can solve including toilet bowl/long bath crack

u try first if all failed just pm me, i will ask ex colleagues his contact number

Perhaps, you can try this method.

Get a few bottles of Coke and pour onto it and let it sit for a couple of hours.

I can't guarantee it will work. No harm trying anyway.

Probably mold stain.

Get the Bleach Tilex tile mold spray. Spray it and wait for 10-15min. Scrub it away.

Get the strong wan if the stain too stuborn.

Becareful with bleach it will corrode the metal part and make them rusty

Try use mild acids.