no problems with developer stain they should get clean with water
fixer: a friend told me to use corega-tabs (dont know a name in english) this are tabs to clean your 3rd teeth.
works well for me
The brand name is Steradent in Australia (denture cleaning tablets that dissolve and fizz in warm water) and I use them regularly to soak reels and things. Leave them soaking overnight and then scrub with a toothbrush if necessary. Never tried it with trays. A thorough rinse in hot water after each session has kept mine in good shape after many years.
I only rinse my trays out with hot water at the end of every session and they still look clean after several years of use. My slot processor was a different story, leaving chems in plastic for extended periods of time made it look disgusting. Once a year I would clean it by soaking in water with Polident denture cleaning tabs. It sometimes took a couple of treatments in the developing slot to come fully clean.
Thanks for the good response everyone - seeing as the staining doesn't present a problem I think I'll go with the 'if it ain't broke, don't fix it' school of philosophy, leave it be and just enjoy the interesting patterns.
My developer trays are stained heavily with what looks like silver build up but is probably a lot of things besides. I use the same trays for sheet film development with pyro developers, and for prints with amidol. I always wash with hot water right away after using my trays and often scrub with paper towels, but the stains build up anyway. I've tried all kinds of cleaners that didn't work. R-9 bleach didn't even work that well. So I finally gave up trying to get the stains out. As far as I can tell, they don't cause any problems.