Do not use permanent glues, such as glues with "gorilla", "super", or "crazy" in their names. They will cause problems in the long run. The wood glue and rubber solution also sound like bad ideas.
These glues could get into the screw holes, which would complicate any service the camera may need in the future. They would make it more difficult to replace the grips in the future. AndThey could get into the screw holes and into the camera, which could damage the camera or complicate any future repair efforts. Also, solvents in some glues could damage the camera body.
Personally, I would use a basic double stick tape, as mattdm suggests. Rubber cement may also work, since it may be easily removed if needed. Another option, depending on the condition of your existing rubber grips, is to purchase replacement grips for a few dollars. They should come with a suitable adhesive.