While Oxalic dribbling of 50mls of a 3.5% solution of 
Oxalic in sugar syrup (which would be 35grams of Oxalic 
in a 1-litre bottle of sugar syrup) is one way to go,
why not take advantage of powdered sugar.

They are in the perfect container to apply the sugar,
and one can rotate the package, shake the bees around,
and otherwise make sure everyone gets exposed to the
poofs of 5-micron sugar dust.  The free sugar is not
going to hurt them at all, as they likely need sugar,
and would be encouraged to stay in the hive and get
used to their (depending on package transport time,
perhaps very!) newly-added queen.

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