If you're crafty, you can make a lid liner to protect the metal from the corrosion. Beyond that, you really shouldn't use meta lids as they will react to the CDS vapors very quickly and contaminate your solution.
As for being ready, just watch for color matching in your reaction flask. When they are the same(color) you'll know there's nothing else to saturate and you can remove the flask from the jar for storage.
On dosage, depending on concentration(CDS) is taken by diluting it with water. ie, a typical glass of water can easily accommodate 5ml of 6000ppm CDS. Though I'd caution against making it too strong as this can/and will irritate the oesophagus which which bring on a host of other problems. And so, if you're drinking CDS and you feel as though it's causing your throat to burn. Then you need to pull back on the concentration and intake.
Beyond that, CDS is very forgiving in terms of dosage and side effects. ie, you won't vomit by taking it. Along these same lines, it's also the weakest and least persistent(in body) form of Chlorine Dioxide assimilation due to it's volatile composition. And so there's that to consider I suppose.
In order of effectiveness I'd categorize the various Sodium Chlorite Solutions as follows:
That said, CDS makes an exquisite topical solution in conjunction with DMSO on cuts and various infection related conditions. Not to mention one of the best lab glass cleaning solution I've ever had the pleasure of using.