re: Inlay using coffee grounds...

Yes CA glue is like super glue, it is Cyanoacrylate. It comes in super thin set, extra thick and gap filling. We use it a lot for repairs and I like it for inlay. You can also use it for a finish on turnings, like for pens and rings.
Where we got ours was here online: http://www.hobbylinc.com/ca_super_glue