Both Hohners are now odor free. After about four hours of their resting loaded with baking soda, I decided to wet them down with a sprinkling of water and then to take advantage of the situation by cleaning all accessible areas with paste made by dipping wet rag and toothbrush, alternately, in the excess baking soda. I worked the reed and reed plates over brushing/ rubbing in the direction of the open end of the reed and back and forth between reeds and on the rest of the plate. I was surprised how nicely this cleaned up the reeds. Then I worked each melodica around under running warm tap water and then immersed them and sloshed them around in warm tap water. It takes a bit more effort than you might think to eliminate all residue; you can tell by rubbing your finger across an area and seeing whether it has a salty taste. Finally, I dried the melodicas with a hair dryer at a distance of about 12″. This didn’t produce any odor; so while some may reappear, that seems unlikely to be a significant issue. The Piano 36 was pretty foul, so I’m really encouraged by these results. I’ll report back if there any unanticipated issues arising out of the treatment, but that seems unlikely. I do think the drying has to be done carefully, as high heat could cause damage.