Thornton's Pyro 2-bath is a hidden gem. Let me tell you, if you've not tried it you are missing out.
Bath A
Water 750ml
Catechol 100g
Sodium sulphite 20g
KBr 5g
Water to make1 Ltr
Bath B
Cold Water 750ml
KOH 100g
KBr 5g
Water 1 Ltr
5 mins A - 5 mins B
Water stop
Alkali fix