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.
A: Yes.  Black Holes (BH) can grow from accreting anything with energy --- including dark matter (DM).
I'm not entirely clear on the second part of your question, but probably the most important thing to keep in mind is that the black hole information paradox is still unresolved.  Answering how information is not lost for any type of particle, including DM, after being accreted by a BH is a very active area of research, and doesn't have an established answer.
A: The information paradox has no particular connection to electromagnetism. Hawking radiation is not just photons, it's any sort of particle. And Hawking radiation in itself doesn't solve the information paradox - the problem is that Hawking radiation is supposed to be thermal, so quantum information of infalling objects has been irreversibly lost, but that would violate unitarity. 
