What glue do you gentlemen use for repairing cork (missing chunks) and for filling the inevitable voids in the grip. white glue and tight bond just make a mess.  (Jon Holland)

Use more grits in the white glue.  (Ray Wallace)

FIX brand wood filler in light mahogany.

I have messed with all of them, and that one is by far the best. Hint: you don't have to do every void. Just do the worst ones and you still get a nice traditional look without it resembling a completely filled production graphite rod.

If a grip is really trashed with chunks missing, I just suck it up and replace the grip. My most common issue is breakage over the upper ring on inletted uplocking reel seats. Some day I will learn to leave more cork over the inlet.  (Jeff Schaeffer)

I use yellow carpenter's glue mixed with cork dust.  (Bret Reiter)