no, this will not help you very much. If the leaf is already dying, it will cause further damage to the leaf. If there is a leaf that is dying, it can mean that it is just time for it to die. If this is the case, cut the entire leaf off at the base of it's stem. The benifits of pruning generally are healther plants. If you prune the dead/dying/algae infested, leaves off a plant it wastes less energy on the damaged leaf and can provide more nurishment to the healthy leaves, and making new ones. Therefore a much healther plant over all.