Using sweeptestall for singleframe collisions

In a recent issue I was having with using a capsulecastall to esentially pick all enemy game objects in an area and deal damage to them, I was advised to use rigidbody.sweeptestall instead to provide better accuracy, I've been wracking my brains on how to get this to work, but I just can't. For an ability that was previous performing a capsule cast on call to pick out the affected targets, how would I then change this to sweeptestall? Would I call the sweeptest every frame for every enemy and create a temporary collider that is the area of my ability? If so what's an easy way to do this and how could I specify that this particular collider is the kind of collider that will set off the desired effect? If this is not the best way to do it, how should I do it?