Q:

Can black holes grow via accretion of dark matter particles?

I'm assuming that the answer to the question in the title is a resounding yes. Since Baryonic matter and dark matter interact via gravitational forces.
If this is the case how is information not lost if, as is presumed, dark matter does not interact via the electromagnetic force?

A:

On top of the other excellent answers I'd like to point out that the accretion rate of dark matter particles is believed to be much smaller. The reason matter in accretion disk is being accreted rapidly is because they lose energy from electromagnetic radiation.
For dark matter particles, in practice the only way it can be accreted is if the particle happens to be on a trajectory that falls into the black hole. Close to the black hole the gravity is completely dominated by black hole so gravitational interaction between baryonic and dark matter is very small.

