  I isolate a combinatorial property of a poset $\mathbb{P}$ that I call the
strong Prikry property, which implies the existence of an ultrafilter on the
complete Boolean algebra $\mathbb{B}$ of $\mathbb{P}$ such that one inclusion
of the Boolean ultrapower version of the so-called \Bukovsky-Dehornoy
phenomenon holds with respect to $\mathbb{B}$ and $U$. I show that in all cases
that were previously studied, and for which it was shown that they come with a
canonical iterated ultrapower construction whose limit can be described as a
single Boolean ultrapower, the posets in question satisfy this property: Prikry
forcing, Magidor forcing and generalized Prikry forcing.
