I found your thread looking for the same answer. I trained all night at the goblins in the stronghold of security and gained 20 levels. from 40 atk 40 str to 40 atk 60 str.. I think there should be better places though I only got around 170k exp.. Lemme know if this helped at all.
Train dung legit until like 5 or 6. Bot some mining or w.e you want using lamps on dung. Go to 10 dung chaos druid spot.
Up to 350k per hour on my 1 def 20 attack, as well as up to 18k strength xp per hour. It was a lot less using the non dung spots, as they are heavily botted by super noobs.