I gave my 9 year old Golden Australian Shepherd ground flax seed in her dinner. This was after 2-3 nighttime accidents. The accidents have not returned since.
Corn silk works wonders for my dog's incontinence.
He was suddenly dripping and peeing in his sleep even though he has never peed in the house in his life. I see that most of the posts have been about female dogs and their spay incontinence but I just want to say that corn silk capsules eradicated my adult male dog's incontinence by 99%. He is a 70lb dog and I give him one capsule per meal twice a day. I also time when he gets water but not reduce the total amount of water given to him. This way he would not have to hold for as long. In two weeks he went from dripping in his sleep every day to needing to go out earlier than his potty breaks. We listened to him when he would indicate wanting to go and slowly his schedule was back to normal. It has been a month and a half and he stopped having incontinence completely.
I will likely give him cornsilk long term since it is inexpensive and effective as incontinence prevention.