Are you under the impression there is only one wall to the crop? The outer skin is torn, obviously, but if the crop contents are leaking out of the outer skin tear, the crop sac has also torn open.
You need to spread open the outer tear and inspect and clean the crop sac tear first. Use saline wound wash by either buying it from the pharmacy or making your own by boiling water and adding table salt and baking soda. The recipe is on the internet. Use Betadine to disinfect the wound before gluing. Be sure the tissue is dry before trying to use the glue.
Then dry with a hair dryer and use the super glue to glue the torn tissue together. Hold the edges for one full minute wile the glue sets. Then disinfect and do the same for the outer skin that's torn.