Bill, Good thread, topic been covered before but always nice to let the new collectors in on what's going on. There are three types of airtites now available to use. The old standard is the airtite with the foam ring which seem to allow the strike to slightly tone but very slowly. There is the direct fit which is also an airtite and allows you to keep the strike the same size as the old cases. Those are good if you store your strikes in the older Anchor racks. They also seem to be holding out the air better than the ones with the rings. Gary Hinz & Bill Cohenour have found a third type which is the same 43mm as the ring type but they have a ridge inside them instead of rhe foam ring. A few collectors are now switching over and no results have been posted as to their quality of keeping the strikes from toning. Their too new at this point. I personally keep mine in the ring type holders and in an airtight gun safe which I've found a good combination for reducing the toning. I'm not sure if any of them will do a 100% drop dead NO toning job.
As far as cleaning (new thread) one can use e*Z*est coin cleaner to do both the brass and silver with above average results. Dip, rinse and pat dry and they look good as new......ask Jamie Martin, he's changing to the new cases and has dipped close to 2,000 strikes......ISH !!!!!
My two cents worth, hope it's some help to you and others. Jeff