The book "Comfortably Numb - A History of the Wall" by Vernon Finch and Richard Mahon is probably the most recent and detailed analysis of the album. It contains the full (and correct) lyrics of all the songs. Page 107 contains the lyrics to Waiting for the Worms, including the megaphone parts.
The transcription on the book and your version(s) have really big differences (no Abbot's Road, no 4 o'clock).
On page 108 of the same book there is an explanation from Waters himself:
"... it's describing the route of the march from Brixton Town Hall, down Stockwell Road, and then Lamberth Road, and over Vauxhall Bridge. It's meant to be describing a route to Hyde Park Corner to have a rally by the National Front."
I don't know if it is allowed to share here a photo of the page where the transcript is shown. If it is permitted, I may take a picture of page 107 with the lyrics and the transcript and post it here.
PS: I sometimes think that the version from the "Is There Anybody Out There" live CD is clearer in the last part of the chant.
Tell me what you hate, and I'll tell you what you do.