That's what I've seen when I've done that. Enormous cuttings take root easily in water. The reason I do that is to save material that would otherwise be turned to mush from frost. I prefer to cut and save, vs. having a clean-up chore to do.
Yes, cuttings put in the ground during the growing season also do well, if one wants to reduce the size. They don't get that big here, having to start over from the ground level each year. Once in a while, one or two don't return, so by bringing some stems in, I'm not at risk for losing all of them over a harsh winter. It's not a thing of saying this is the best way to propagate, but a way to save and use what would otherwise be ruined.
These pics are from a couple years ago. I did the same last winter, and this year. They are in a half gallon laundry soap jug, which has a great wide opening.
I haven't taken pics of this years' props yet. On my to-do list for this weekend.
The goal for me isn't to have an indoor plant, but to keep the cuttings just alive until they can go in the ground in the spring and have 8-9 months to establish before the next freeze. The roots are hardy here but the above-ground parts are not. This is what a Brug looks like in the spring here.
