Take your condensors into a electronics supply house, if you have one, and they may have a bench model/display model of a multimeter or capacitance meter to give yours a test. You will have to ask very nicely. That way you can toss those that are bad and keep the good ones.
A good multimeter you take care of is a worthy investment, because when you need it...it is an excellent tool for car, bike, house wiring, etc. There are YouTube vids of how to use them to test things in the circuit and out of the circuit so you learn to use them properly. Also, be safe when taking measurements of high voltage AC as it does not take much to kill you in the wrong conditions. Keep your fingers off the meter contacts as they can change the reading if you have your mitts on the probes when taking a reading. A set of small alligator clips soldered to a wire with a brass tube with a slit down the side that is a friction fit on the probes works well to have hands free on at least one probe. Or buy a set of probes with the spring loaded ends that have a little wire clamp.
This works when you can hook the probe onto what you are measuring... sometimes you cannot.