Using a syringe to reglue sewn cuffs and hems eliminates the need to tear out and resew linings. But you can’t see the glue going into the hem, so you should practice your technique beforehand. Practice makes perfect.
To perfect your use of a syringe to reglue cuffs and hems on suede and leather garments with sewn-in linings, practice on a simulated open hem using a piece of paper. You can then employ the technique with confidence.