Securing Makiwara Pad to Post

[JCavin]

So I made a pretty traditional makiwara post and pad. The post is a 2x4 with the cross supports on bottom. Wiggle room in the dirt and such. Not too flexible, not too hard.

The pad is a bunch of straight pieces of sisal rope wrapped in more sisal. Basically it looks just like the straw ones that you see the traditional guys using.

My question is:

How the crap do you secure it to the post? I used some dropline for fishing. That worked pretty well until this morning. The string is starting to fray. I'm looking for some good, and easy, ideas of how to keep it on there. Preferably a way to take it off and turn it as well. That darn thing is way harder than it looks. After a few hundred hits it feels like i'm hitting the 2x4. Thanks guys.