It can be done but having the proper equipment to do it is tougher than one may think. We pull otoliths from WAE every year for age study. I've done it with 2 perch about 5" long and it's a job. It's very easy to destroy the otolith if you haven't had some training.
They are dried and wiped clean, then set in a small receptacle that resin is poured into. When it sets hard the mold is sawed in half through the otolith. The cut is cleaned and placed under magnification and they appear somewhat like rings of a tree yet a bit more complex. Most Biologists are looking at year class but the trained eye can get down to within a week-accurately.