Bandhas (locks) are energy locks and help move vital energy upward when combined with meditation. Moolbandha and Mahamudra help control the spinchster muscles thereby increase control on nightfall. Although Nocturnal emission is a complex phenomena involving various factors, these bandha and mudra do help.
PS: Jalandhar (good for thyroid gland), Uddiyana (good for abdomen cavity and organs like liver, kidney, spleen, intestine etc) Moolbandha (good for reproductive system and transmutation)