OF COURSE it's desirable to learn hip belay and even bowline on a bight for tie-in..
In lieu of a harness, 15 feet of tape or even that much rope, make a fairly decent sit-harness. You can consult mountaineering handbooks for method.

You can't hang on bowline around your waist for any length of time. It's deadly.

The hip belay is more useful. In my opinion at least, It definitely has practical applications for the odd moment and marginal circumstance. "Aiming" is a very important concept to consider using this technique.

I started climbing in about 1970 and first encountered belay plates in 1977. Note that Munter Hitch is highly effective replacement for belay device and much more effective than hip belay, assuming you've got some sort of harness.