Jk. It is! But you’ll need a cord stop. (What YYF uses on theirs). From that point on its sorta self explanatory. (Take cord, fold in half, put cord stop on top [double end], tie on clip, and viola! Holster!)
Although I make holsters if you’d like to buy one [they’re $10]. You can see them if you click the link in my sig.
If not follow that little guide. Hope it helped
EDIT: or you could just tie the cord to the yoyo then tie it to the clip. (Though doing these probably wont turn into any sort of eye candy, and if you tie anything it has a chance of coming undone, so keep that in mind)
With the materials you listed you can fashion a decent holder but I have found that they tend to not hold up as long as a good paracord holder. Thats what legyoyos holders are made out of as well as my Toxic holder (which I have been rocking for 1 year now with no signs of breaking.) You could also purchase some paracord too and try your hand at making your own if you want.
My girlfriend and I make yoyo holders out of yoyo string all the time. It is very, very simple. You just need 3 yoyo strings and a knife (to cut them to size).
I find it much easier and more sensible to use objects I already have laying around than buying paracord or a pre-made holster, no matter how high the quality.
Honestly, you don’t need to buy a paracord holder that someone else made (they’re super easy to make). Just take your old string, and make two loops on either end (like you would do if you wanted it to go around your finger). One end goes on the yoyo, and one end goes on your belt loop. Problem solved.
Here’s a thread about some yoyo holders I made a while back, I had the same thought as you and decided to see what I can come up with, let me know what you think!
I can even make a tutorial maybe if people like it.
It’s really easy to make one out of a carabiner (like a water bottle one) and then drill a hole in the bottom. String a hair tie through it, and you have a perfect yoyo holder.