Please explain British saying:"a complete Horlicks"

I saw this in a BBC article:

From the context I assume it means a screw-up, or something similar.

What’s the origin of this saying? Did someone named Horlicks really screw up big time?

I imagine that it’s a politer way of saying "a complete bollocks’, although I’ve never heard it before.

“Horlicks” is a hot malted drink like you have before bed. No reason why it should be used in this expression other than it sounds kind of similar.

I think it’s probably a reference to the TV advert ona while back - a woman goes about a day in the life, everything’s going wrong, and she reaches the end of her tether. “OH . . . HORLICKS!” she screams. And we cut to her, with her feet up, sipping a mug of her favourite malted beverage.

I intend to use the phrase as often as possible from now on.

Yes, it is a new-minted rhyming slang for bollicks- and I have heard it used in anger or in jest once or twice…

BBC Radio 4 said this morning that it was Parliamentary slang for a mess, inspired by the messy sludge left in the bottom of the cup after having a drink of Horlicks. Never having had Horlicks or having been to Parliament, I can’t comment.

The phrase “a complete Horlicks” became popular as a euphemism after it was uttered in public by none other than HRH Princess Anne, I think back in the Seventies. I don’t know if she originated the term though.