A follow up question regarding the oa/gly treatment - the document Dawn_SD linked to above states the following:
Practical application: beekeepers have been looking for an inexpensive, fairly rapid acting, easy to apply miticide that doesn’t leave residues in the combs or the honey, and that doesn’t slow colony growth or harm the queen. Oxalic acid dissolved in glycerin, applied on a removable substrate, appears to fit the bill. Applied on a shop towel, it causes immediate mite kill, and then continues to kill mites over a period of a month—spanning approximately two varroa reproductive cycles.
This seems to indicate that this treatment does not affect the honey stores in the hive in terms of human consumption. Dawn_SD, you cautioned otherwise. Is there any more recent research on this?