Yes there is no direct way to play gestures with script. However, you can trigger script with gestures by triggering the script from text in the [Replace with:] box in the gesture. An example is the commonly used hug script. This script is triggered when a user wearing the scripted object types '/hug username'. There is a gesture called huggie which is triggered when the user types '/huggie?' . Take this gesture and put '/hug' in the [Replace with:] box. Now if you type '/huggie? username' the /huggie? will trigger the gesture and the gesture will change this to /hug which will then trigger the script. username will then be read and the script will run as if you typed /hug username.
Note: changing the gesture trigger to /hug same as the script trigger will not work because the gesture will take the /hug out of chat before the script can see it. So you must use the gesture [Replace with:] box