Read another post that said you need to have fish scales in your inventory or it will not cast. Have not tried it, but if not, will come back and add yet another post.... You will sicken from my gabbiness yet....
Just bought two in bazaar for 50 pp each. Seemed awful low for 5 charge EB item... My main has a fishbone earring which I have found indispensible on many occasions, so still seems cheap to me. Will put it on my alts and use when really necessary... can be a life saver.