I'd have to agree with BenMax on this - I think you'll get good improvement with some re-conditioning and positive reinforcement for pottying outside (and I personally always prefer trying all behavioral methods before I resort to any meds). Based on my experience, it might take longer than just 1 weekend, but JRTs are usually pretty smart cookies
- the key is just consistency.
I'd also recommend finding ways to provide mental stimulation - he's getting exercise, with your daily walks
but sometimes if intelligent dogs don't have mental energy outlets, they start misbehaving in various ways. You could try a treat ball - a large hollow egg-shaped plastic ball with holes in both ends. You put kibble in the ball, and set it on the floor... the dog uses his nose & paws to roll the ball around and make the kibble fall out the holes. (It's fun to watch, too!
) One of my fosters never ate meals out of a bowl - I'd put his kibble in the ball instead! Another great (and cheap) suggestion is to slice a 2" opening in a tennis ball - then squeeze the sides of the ball so it 'opens' and let them smell/see you put some kibble or treats inside it. They have to use their paws and mouth to 'squeeze' the ball open and get the treats to fall out.
Hope this helps. Good luck to you!