I also am familiar with it from where I grew up in California. It reminds me of "My Fair Lady" with Audrey Hepburn as a poor cockney speaking flower seller and the phonetic expert [Rex Harrison] who was able to recognize a person's precise place of origin by his/her words and pronunciation used. He took her in to teach her 'good' English and win a bet.Haha! British .....well it was in the part of the country where we lived.
Idioms vary all over England.
It would be a bit more like 'sulking' and 'navel gazing' than just grumbling. :)
I was in the mulligrubs when I first read your above response because I could not immediately remember the name of the movie.