Build up in drum processor

Hi, I've taken to using an old ubnicolor drum instead of trays, I started using it for colour and now use it for BW (basically because I prefer the work method and lack of smell, please no debates about the merits of trays !)
I now find that there is a black (silver ?) residue building up in the drum which comes off onto prints (it washes off so no permanent problem) which is a bit of a pain. The print I did after a reasonably thorough clean all of this precipitate came off into my dev.

I do clean the drum between prints - using old cotton clothes- but the build up is getting gradually worse. I've left it to soak overnight with a few drops of sepia toner bleach in the wash water but would be gratreful for any other ideas.

Cheers Digiconvert.

Nova have a product called Tar Buster which can be used to clean their slot processors and works very well at getting rid of build up. I think that there are a couple of cheaper supermarket options around such as the infamous Cillit Bang which might be worth a try.

I process by drum, but use the Jobo 2840. It's won't help answer your question, but I don't get any noticeable staining, could it be difference in the plastic formulation. All I ever do after use is to wipe them out with an old tea-towel.

The sepia bleach did the trick ! Must be silver precipitate, the Iodine bleached that out. Thanks for your advice.

Cheers CJB