If you are using a flat 2 core flex on your lamp you and cant fit a cord grip, try this Flat Cable Strain Relief. Just add it to the flex insid ethe vase or pottery base and it will stop the flex being pulled out the hole.
For flat 2 core flex 0.5mm or 0.75mm only.
Must be added during the assembly of the lamp. Use the quick fit grip A23M if not.