using an aux is all good for stuff like compression, gating, eq, etc... but for any time based effects such as reverb and delay, they should be sent using the sends on the PT channel strip. Here's a quick run through of how to do so:
- Create an Aux track and set the input of the channel to a bus
- Throw the reverb/delay plugin you want to use on this aux track and make sure to have the MIX setting of the plugin all the way to 100
- On the tracks you want reverb/delay on go to the sends and select the bus you picked as the input of the aux track
- Make sure the send to the Aux track is in "Pre" mode (should be a little P button)
- Throw the sends volume all the way up to 0dB and adjust to taste
Doing reverb/delay in this way will allow more control over the reverb compared to throwing the reverb on a aux strip. With the sends, you can select how much reverb you want each track to have by adjusting the levels of the sends. This will save CPU as well because you can send as many tracks into the same reverb as you want. Give it a try, and let me know if you need anything clarified!