  We present an alternative "encapsulated" formulation of the Selective
Frequency Damping method for finding unstable equilibria of dynamical systems,
which is particularly useful when analysing the stability of fluid flows. The
formulation makes use of splitting methods, which means that it can be wrapped
around an existing time-stepping code as a "black box". The method is first
applied to a scalar problem in order to analyse its stability and highlight the
roles of the control coefficient $\chi$ and the filter width $\Delta$ in the
convergence (or not) towards the steady-state. Then the steady-state of the
incompressible flow past a two-dimensional cylinder at $Re=100$, obtained with
a code which implements the spectral/hp element method, is presented.
