Hands shouldn’t be used in Uḍḍīyana Bandha,
the effect should come from the exhale which
starts in the navel, as if pulling up a piece of string.
It must be pulled up and brought closer to the Maṇipūra.
If this is done properly, then very little to be done afterwards.
Exhale is followed by a small jerk as Uḍḍīyāna pulls the Mūla up.