G'day Big Mick,The usefulness depends on the basic key and/or the skill of the player. I've made use of players of old wooden clarinets, in the key of 'C', for Australian traditional groups, but this one is probably in Bb. A really skilled player can play it in any key ... but that's neither you nor me!
Instruments are usually wood ... or wood-looking plastic for cheap ones ... but metal instruments have their proponents. I saw some vaguely eastern (Turkish?)ones in metal on one of the American instrument-sellers' sites (Lark in the Morning?) but these were in the key of 'G' and so more useful for less adept players.
I noticed some metal ones at a local (Sydney, Australia) shop Accordions 'n' Folk ... and Christiaan Dolislager, proprietor of same, was the player of the old wooden 'C' clarinet I mentioned above. I'll run the secription past him - but it doesn't relate much to your area, anyway.
Regards,
Bob Bolton