Those folding japanese saws are great for sawing soil/roots/dirt out of cracks and of course for sawing small bushes/trees that are too big for clippers.  A regular screwdriver is good for smaller cracks. 
  
The stiffest wire brush you can find will be good for cleaning surface lichen/moss. 
  
Highly recommend goggles and face mask while cleaning to keep that shit out of your head.  Inhaling lichen/moss is probably not good for you, and is certainly painful in the eyes. 
  
Those are the things you otter use.