  This paper investigates chaos and chaotic phase mixing in triaxial Dehnen
potentials which have been proposed to describe realistic ellipticals. Earlier
work is extended by exploring the effects of (1) variable axis ratios, (2)
`graininess' associated with stars and bound substructures, idealised as
friction and white noise, and (3) large-scale organised motions presumed to
induce near-random forces idealised as coloured noise with finite
autocorrelation time. Three important conclusions are: (1) not all the chaos
can be attributed to the cusp; (2) significant chaos can persist even for
axisymmetric systems; and (3) introducing a supermassive black hole can
increase both the relative number of chaotic orbits and the size of the largest
Lyapunov exponent. Sans perturbations, distribution functions associated with
initially localised chaotic ensembles evolve exponentially towards a nearly
time-independent form at a rate L that correlates with the finite time Lyapunov
exponents associated with the evolving orbits. Perturbations accelerate phase
space transport by increasing the rate of phase mixing in a given phase space
region and by facilitating diffusion along the Arnold web that connects
different phase space regions, thus facilitating an approach towards a true
equilibrium. The details of the perturbation appear unimportant. All that
matters are the amplitude and the autocorrelation time, upon which there is a
weak logarithmic dependence. Even comparatively weak perturbations can increase
L by a factor of three or more, a fact that has potentially significant
implications for violent relaxation.
