It's really not a good idea to include the receptacle(the part where all the flower parts are attached) in any freezing attempt. Compared to drying just the stamen (or even better - just the anther), drying the receptacle takes an incredibly long time and will also delay the drying of the pollen. Absolutely, a recptacle will not dry optimally in just 1or 2 days, and will keep the pollen from drying sufficiently, too. Pollen must be dry before freezing. Moisture is the most devastating to pollen life, but success with pollen freezing depends on a lot of variable:
-- how dry the pollen is (drier = better)
-- plant species
-- temperature (minus 10°F is better than zero, which is better than 30°F)
-- age of pollen before freezing
-- your freezer (defrosting or non-defrosting)
-- ???
Not to say freezing pollen can be successful for all plants, and there may be a few exceptions that I don't know about, but this advice will hold true for all temperate climate plants. (I don't know about tropicals.)
