Sorry, but I have no way of knowing how effective Rockwool will be. I expect not a lot, because soundproofing requires mass (which doubling and tripling up on drywall gets), and Rockwool isn’t going to have anything near the kind of mass that drywall does.
As far as dealing with it, I expect most people simply don’t use the system when other people are sleeping or doing something that needs quiet.
BTW, forgot to address the neighbor issue. With free-standing houses, I can’t imagine how they could be disturbed. It’s never been a problem for me.
Regards,
Wayne A. Pflughaupt