This is an iteresting debate. I find that using silica gel packs or similar moisture absorbing material INSIDE a pack is quite risky. Even inside the cabinet could be an issue - depends on the size of the cabinet. It can actually attract moisture into the packet / cabinet. I know that pharmaceuticals do this, but that is done after a lot of research. It could be that the drug itself is agroscopic (attracts moisture). I have found that using such packs inside a binocular case only made it worse & the binos got fogged & ultimately got mouldy inside the lense. Others are likely to have just the opposite experience! It could be something to do with relative humidity in the place where you live.

The oxidisation of brass (similar to rusting) can be prevented. The real issue IMO is the age of the brass & the brittleness of the cases. I have seen old British factory ammo with spot crimps corrode at the spots & develope perforations. Some old ammo of British classics split at the neck when fired for the first time. I presume this is due to change in metal hardness / maleability / ductility over time. Does the oxidisation process reverse the anealing effect on the cases? The old brass had more lead & other impurities in them. Modern brass is a lot purer & made with greater control. The alloys can now be tailored to specific ratios of different metal content.

I would separate the ammo into corroded ones as "keepers" for collection or sentimental reasons & the good ones without corrosion as "shooters". I would use the dehumidifying stuff in the room rather that the cabinet or the packs.

I would really like to know the views of more experienced people on this subject.