My father has been attending Alzheimer's day programs to give my mother a much needed break. He has been grabbing other clients' breasts and now may be kicked out of the program. He has been rejected by a number of nice memory care programs and homes because of this behavior. We have tried some medications, but nothing seems to work.
I would have edited my post but for some reason, today I am not getting the edit option.
Seroquel helped a bit, mostly by making him so sleepy he napped most of the day. He's gotten used to the drug now and doesn't sleep as much. Sedation is another avenue to consider. Our neurologist explained it as needing to "slow his brain down" from the excessive sexual thinking. Slowing down pretty much amounts to making him sleepy instead.
Persons with SIB cannot control their own impulses. They don't, they can't, see anything wrong with what they're doing. They may believe their target wants to be subjected to their attention. It's dementia and delusion, and all the lecturing and threats in the world won't change their behavior. Medication might help somewhat, but there's no guarantee.
We too worry about placing Dad in a facility, when that day comes. Just because he can't control his desire for "fun times" doesn't mean other people should be subjected to his acting out. At this point, though, he's become so immobile he's little threat. I hope you can find a way to treat your father. This is a very distressing behavior! You're clearly trying to give him the care he needs.
Sadly, this is actually very common with elderly men.