Thanks for the links.

I've finally found the article I was thinking of and its follows very similar lines to those on the link. It recommends 30g anhydrous sodium sulphite in 500ml of water to which is added 5 ml of Rodinal making a solution of around 1:100 rodinal to water. the developing times are greatly extended though, APX 100 requiring 18 mins instread of the 8 for 1+ 25 rodinal.