Uses for spent pyro developers

Hello,

Are spent pyro developers of any use for adding fog density to films after development? For instance, say I have a roll of film developed in any standard developer, and I decide that it would print better with a bit of fog. Can I dip the film in some used PMK to get that? I know this sounds dumb to seekers of The Standard Print, but sometimes I like the way fogged negs look, and I think that this might be more predictable than using any random bit of expired film.

Right now I just save the stuff up and take it in to a haz-mat center along with my spent fixer.

If this won't do the trick, any other suggestions, other than sandwiching film?

Thanks.

I think the stuff oxidized fairly quickly and it wouldn't be easy to preserve for reuse. I dump it down the drain.

If you want to try it, use it within an hour of mixing. It gets dark/muddy pretty fast just sitting in a tray.

So, the general stain will be produced only by "active" developer. I knew this was the case for the density-linked stain, but thought that general stain (fogging) might be possible after the fact. Thanks for the reply.

Any other chemical-based suggestions?

Well, the latest instruction about PMK says the after-stain (which you originally saved the developer for) is useless, but no harm in trying it. I bet tea/coffee/caffenol-c would add a stain consistently at any time if you wanted.