I see two errors in previous posts. The stain in PMK is not an overall stain, though it may have an overall component if used as originally proposed in The Book of Pyro. Even when it has an overall component, it also has a component that is proportional to the silver density.

Second, none of the Pyrocat series need be short lived. The A solution can be put up (as we say in canning vegetables) in propylene glycol by the substitution of a small amount of ascorbic acid for the sulfite. It then lasts as long as you want to keep it. You will probably want to use it, though, before you get senile.

If the color is the decider, you can use pyrogallol in the same formulation as Pyrocat, but use 2/3 as much. It also is quite soluble in glycol.

In some respects, the Pyrocat series is more versatile than PMK, but that is a matter of opinion, as is just about everything we photo nuts do.