The secret brush techniques Fireburst and Icestorm both have the effect of slowing down time for enemies, just like Veil of Mist. This includes slowing down the cannons and spinning gears in Wawku Shrine. Because Fireburst can be obtained before Imperial Palace via Fireburst Early, this allows NG Any% runs to skip Veil of Mist despite it being intended to be required in Wawku. The only known exception is Blight, whose quickdraw attack will only be slowed by VM. He can still be defeated without VM by waiting for his spinning sword attack.
When both VM and Fireburst are available, VM is generally preferable as it uses less ink and does not have the brush lock-out period that Fireburst and Icestorm have. These effects make it more difficult to use Fireburst to defeat the gold cannon at the end of Wawku.