Shaking off the thin peel from the grains: If one had kernels which were removed from before Shabbos from their stalks and are still mixed with their chaff they may not be sifted [out] with a Kenon or plate due to a decree that one may come to sift them with a sieve and sifter in which case one is liable.
[Furthermore] even to do so with two hands, meaning to shake them from one hand to another in order to separate [the grains] from their thin peel [is forbidden]. Rather one is to sift them using a single hand placing into it all his strength in order to differ from the method that is used during the week (and thus not come to sift in a sifter). [See Q&A]
Summary-Shaking off the grains in order to remove their thin peels:
Is forbidden to be done with a vessel, or even through shaking from one hand to another. Rather it may only be done through shaking it strongly in one hand, [and even then one may only do so to eat right away].
May one use his hand to sift food for right away use by spreading the fingers slightly apart and pouring the mixture over his hand?
No as this is not considered the way of eating, and it is thus equivalent to using a strainer.
May one shake grapes/peanuts/berries from hand to hand in order to get rid of the peels and stems?