I’ve read the article that Iadom link lead to but wanted to ask if liquid detergent could also cause blacking of the soap tray even though the only thing the soap tray is used for is conditioner?.
The blacking is more about moisture ( damp ) i think but obviously the detergents could be helping, cool washes don’t tend to “steam” in the tray like hot washes do. ( thats my theory anyhow ) 😛
Centrally heated homes, warm damp environment… perfect for bacteria to grow.
If they’re not cleaned fairly regularly then you will get the black mould appearing for sure. I think people just assume that a washing machine (among other appliances) will somehow magically clean themselves.