Liz - a goose with a grudge is more likely to work itself into a display of size where it is going to lose wing feathers than a calm contented one.
A friend's goose once had a major loss of flight feathers and I ended up with a bag full for the dulcimer.
They don't need any preparation before use and do look "fancy" when you use them for playing. They also give a different, lighter tone compared with plastic. That said, plastic is more durable. Quills will wear down fairly soon, they start to fray at the playing edge and after a while need to be trimmed with a sharp knife to so you are using solid quill. As a result the quill gets shorter and eventually needs to be replaced as you don't have one left to play with.
By all means use a quill for show, but do your main practice with something else.
Quack!
Geoff the Duck (Keep your hands off OUR feathers...)