Although I haven't lived in Ohio for many years, my brother still lives there and when I've visited, I have open carried in Cuyahoga and Lorain counties.
Most of the open carry time was on the west side of Cleveland and most of Fairview Park. A couple of trips out to the Elyria area and you've got the extent of my open carry range!
Never had any problems in any of the fast food type restaurants (McD's, BK, etc) and evidently nobody called the local police with a MWAG complaint.
Obviously these were summer trips as I'd be concealed nicely during winter.
Although I've been stopped for open carry in Florida (where I live) at least three times, on all occasions, I was left to go on my way and still open carrying. The rules in Florida are a bit strange, but workable for me.
I never had any contact with the local PD in Ohio while open carrying.