As an officer, I always think blanket advice like this is a trifle dramatic. Outside of work I'm a normal bloke, I watch football, go to the pub etc. Going into the police station does not mean that I suddenly want to screw people over and make their lives a misery.

There is not really a vested personal interest for me to get people charged and convicted, beyond my professional obligations to victims of crime. I am supposed to carry out a thorough investigation and present all the evidence available, either supportive or not. If court or somebody else then decides that there is not sufficient evidence then it does not really have any bearing on me. I never know any party involved personally, so why would I care about trying to trick people into confessing stuff they haven't done?

I get that people have not always had good experiences with the police, but your best bet is to just talk to them like normal people. If they tell you they suspect you of a crime, just ask for a solicitor, police have to ask you at the start of an interview, on tape, if you would like a solicitor. It's not really a right they can deny you without it being obvious to anynody watching the recording.