Is it permissible to collectively recite the dhikr "La ilaha illa Allah" in the mosque, then make du'a and dedicate the reward of the dhikr to the deceased?

The collective dhikr (remembrance of Allah) in the form of "La ilaha illa Allah" (There is no god but Allah) in the mosque, accompanied by supplication, and dedicating the reward thereof to the deceased, was not practiced by the Messenger of Allah, peace and blessings be upon him, nor by his companions. Nor has it been authentically transmitted from the righteous predecessors. Therefore, it is an innovated act, and "whoever performs an action that is not in accordance with our matter, it will be rejected." Those who engage in this act should be advised with wisdom and gentleness.