Rose canes make excellent arrows. I've made a few but mostly use native cane or hardwood shoot shafts like red osier, viburnum and sourwood. All of these have a natural taper with weight forward properties and more adaptable to different bow weights. If you cut the canes long you can pick the section that best suits the spine you need once they dry. In many cases they are more durable than doweled shafting because the growth rings go around the shoot unlike doweled shafting which basically violates the growth ring the way they are made.
If you are going to collect natural shafting be sure you cut only 2nd year or older shoots. When a shoot grows it gets to it's ultimate length the first growing season and will have only leaves(or leaf scars this time of year) along its length. The second growing season the shoots will have small branches growing from the leaf scars from last year.
In the video the guy used string to bind his shoots in bundles to keep them basically straight while drying. More straightening is needed later. I like to use rubber bands to bind the bundles. As the shoots dry they shrink and the string will loosen. Rubber bands keep the bundles tight as the shoots shrink.
Some folks like to unbundle and hand straighten the shoots every week or so so when the shoots are dried it only takes a little hand straightening to get a shootable shaft.