Before beginning, Ven. Kenjo Igarashi lit incense and then cleansed his hands in the smoke. After moving the statue of Nichiren he cleansed a large calligraphy brush with the incense smoke and proceeded to dust the statue.The annual cleaning of the altar includes dusting the inside of the Butsudan.
Here’s a video that includes 125 Mandala Gohonzons inscribed by Nichiren Shonin.