Here is the step by step procedure for deleting stored effects
This article refers to Twinkly Generation II
This feature will clear all the customised effects, freeing up memory on your controller. It can be quite handy if you're experiencing memory issues while creating a playlist.
To remove all the effects stored in your memory, simply select the option Delete effects from device/group menu, the command is located within the device/group settings. Open the relevant device in the Twinkly app and tap the three-dot menu (⋮) in the top-right corner to find the desired option.