If it's a tactical/survival type knife, part of the function of having cordwrap is that you can unwrap it and use it in a pinch (bootlace, guy-line, first-aid, etc). So dual-wrap it really tight with paracord and leave it.
Otherwise, any two-part apoxy works well. Also, any of the "goo" products work okay too (Shoo-goo, Plumber's Goo, Etc).
Cheers,
psr