  We consider entropy generating flows for fluids that achieve a steady state
in the presence of a driving electric field. Having chosen one among the space
of stationarity constraints that define such flows we show how energy and
momentum relaxation are related in the presence of dissipation. Furthermore, we
find that if such a fluid obeys Onsager reciprocity then the incoherent
conductivity must be identically zero and consequently makes no contribution to
the observable AC or DC charge conductivities.
