I’ve just had a thought. Why modify the grooves when we can make our own grooves? It’s probably better that way.
Got my cane strap today ( it was OOS so I had to wait). The guy in the video must’ve did something to his strap to make it stay on because mine just slide off.
So I fixed it. 
https://s4.postimg.org/nj787xtbx/20170817_102836.jpg
Now that it looked like a crappy old cane no one would suspect it’s a concealed weapon.
And the Cold Steel folks are really helpful for me. Here’s the Emails:
ME: I bought your Heavy Duty sword cane from Walmart. I received it today. Very nice I like it. I noticed that the O-rings looked a little dried out (probably from storage).
Can you tell me what size those O-rings are or that I can order some from you?
Thank you for your attention
William
CS: Your receipt please
ME: (Submitted screenshot of Walmart order)
CS: (Sent letter with two O-rings in it)
ME: Thank you for the O-rings for my Cold Steel Heavy Duty sword cane. Now I have one question before I install them, what lube would you recommend to preserve the O-rings?
Thanks again. William
CS: You can use a light coat of mineral oil to keep them new.
ME: I thank you again Sir. Not only the sword cane is terrific but so are you
CS: Thank you, it is always nice to get positive feedback. If you need anything else please let us know.
You really want to cushion the blade while in the scabbard. A good way to do this is pull of the factory cane tip , which you are going to want to replace with a regular therapeutic cane tip anyway, and insert your cushioning material from that end. Sponge or closed cell foam work well. If you don’t do this, the blade/handle joint will loosen pretty quickly. Your other alternative is just to carry the cane around, but not use it. That looks odd.
Also, don’t go nuts with the mineral oil. The round handle is already pretty slick if you need to choke up on it.
I think I’m going to stick with silicon spray. They work pretty good and they dry up. I sawed off the tip and replaced it with the real cane tip. Now that it is shorter it is more comfortable.
The o-rings I ordered from the place linked upthread arrived today. They work well and are cheap enough to permit a lot of practice drawing the blade.
I guess I didn’t link .
So what size did you get?
11/16" inside diameter, square cross section.
Thanks. I’ll check into it.
The more I see that duct tape the more I disliked it so I fixed it. This time I’m in possession of the sword and not the shaft in case someone tried to take it away from me.