That's the nature of angora. The fibers are so soft and silky, they will just fall out. Eventually, all those that are going to fall out will have already fallen out, so the shedding will stop. But you may be left with a very sick looking sweater.
I honestly think freezing angora is an urban myth. No one can explain why it works, so I don't think it does. If anything, maybe it works temporarily while the fibers are still frozen, but I imaging it will thaw very quickly, like as soon as you let it warm up enough to put it on.
I say just carry a lint brush at all times. Angora is too pretty to not wear.