The distributions of "time of flight" (time spent by a single fluid particle
between two crossings of the Poincar\'e section) are investigated for five
different 3D stationary chaotic mixers. Above all, we study the large tails of
those distributions, and show that mainly two types of behaviors are
encountered. In the case of slipping walls, as expected, we obtain an
exponential decay, which, however, does not scale with the Lyapunov exponent.
Using a simple model, we suggest that this decay is related to the negative
eigenvalues of the fixed points of the flow. When no-slip walls are considered,
as predicted by the model, the behavior is radically dfferent, with a very
large tail following a power law with an exponent close to -3