There is a good explanation here:
Red raddle and Cardinal Red were two different things. Red raddle was a traditional ochre pigment mixed with limewash. It gave a matt (dull) red finish.
Cardinal Red was a branded polish (wax- or oil-based) intended for use on quarry tiles but often used on Lancashire brick. It gave a high gloss finish when polished.
You can make red raddle yourself. Cardinal Red is difficult if not impossible to obtain.
I used to live in Salford too. :-(