It’s really annoying in public places when I’m trying to stop my bike. Please explain
NEVER lubricate the friction surfaces of your brake system under any circumstances. There is NO time where this makes sense, ever.
Do check the duplicate question for answers on how to reduce squeal.
Or embrace it - I had some canti brakes that would make hideously loud noises under hard braking, but under gentle braking they were silent. After a while I realised that is really a feature, cos hard braking squeals is like a car horn and alerts people to a possible danger.