So what's the way you did it in real Tibia? I'm sorry, but I've heard "I REMEMBER..." arguments countless of times, and it almost always turns out to be wrong. I'm not saying that's necessairly the case, but you're not even telling me what exactly is wrong. So how am I supposed to refer?
I've just checked and managed to double the three most-east rotworms, by luring them close to the hole. So it's 8 in total now:
I've also doubled the skeletons by roping them while I was there.
So it definitely does work. You must have been doing something wrong. I could explain what exactly and prove why it's not the correct way, but you're not providing any details. Memories tend to become crooked overtime, but Cip files and old .rec files don't lie.