It’s fairly straight forward. Rhyming slang uses a two word phrase and the word that does not rhyme is the slang term that is used.
Hampton Wick, (an actual part of London) rhymes with prick so Hampton, the non rhyming part, becomes the slang term.
Like butcher’s hook, look as in ‘give us a butcher’s at that.’
Or rabbit and pork talk. As in she doesn’t half rabbit.
Chas and Dave wrote a song about it, called rabbit.