The "Finisher Brown" is probably a potassium bromide solution, the "Finisher Blue" is probably Benzotriazol.

The first developer (Amidol) is very, very soft-working. Develop until the hihglights are just a little pale. A quick rinse in water, then into the second dreveloper (Catechol).

I tried it (out of curiosity) without finisher first: The paper went mid-grey immiediately in the second developer. Poured in a clunk of blue, tried again: Very nice result.

I have not tried it with Azo, but it is a different formulation to the one suggested for that.

PS: The translated instructions aren't really vague, just badly translated. It all makes sense in German - even the English instructions make sense when translated to German!