  We show how the hopping parameter expansion at order $\kappa^2$ and
$\kappa^4$ can be exploited in the simulation of lattice QCD with two flavours
of degenerate Wilson fermions. A natural extension of this idea is a
"UV-filtering" by using rooted polynomials. These approaches can be easily
combined with, for example, mass preconditioning. First numerical tests are
performed for the Wilson gauge action at $\beta=5.6$ and $\kappa=0.156$ and
$0.1575$.
