Has anyone successfully used this hint?

In Terminal, after copying and pasting the proposed command line and modifying the particulars to match the specifics of my device, hard drive and intended backup location, upon hitting RETURN, the Terminal responds with ">" and nothing more. Successive RETURNS reproduce the ">" response and only exiting the Terminal window terminates this condition.

Incidentally, rysnc is functional and I have used it for other file backups.

Sounds like you may have not properly closed a set of quotes in your command or something like that. I'd check and make sure there is a closing quote for each opening quote (remember if you copied and pasted them, they may be curly quotes (not sure the 'technical' name for them) and the terminal won't recognise these as quotes - I have this problem all the time when copy/pasting from emails. If it still won't work, can you post the exact command line you're using?