Im not sure exactly why you want to be using it but ill give advice anyway. To get the ex tele to come out you need to hit the R2 on the up motion of the down up for tele. This will make it more reliable.
But like i said not sure exactly why you want to use this unless you absolutely need it to and a match. Mid match this isnt very useful cause you are using a bar for not very much damage. Plus regular jump kick tele gives great options for rain on your opponents wake ups.