Discombobulator grenades are extremely useful as both innocent and traitor these are some of the occurrences I've had in which a discombob has come in really handy.
Traitor
>last inno camping in a room hugging door
>last inno camping a trap or room in which you will die if they press a button
>general diversion
>knocking people off edges of certain maps
Innocent
>known traitor camping in a room hugging a door
>known traitor camping in a room watching a door open door throw grenade in wait 5 seconds rush in while he's staring at the ceiling due to the effect
>getting people out of glitch spots though it does not happen often there are times where although a crowbar will not get the person out a discombob will do the trick
Though there are other little situations these are the main ones I can think of happening to myself personally.