Koshering Oven and Stove

Hi Rabbi, When Koshering the oven/stove, you are not supposed to use it for 24 hours before koshering. Can you use the stove to boil water for koshering other utensils/use oven for kosher for passover food during the 24 hour period?

Mikva

Hi if i bought new Keilim for Pesach but we cant even go to the Keilim Mikve due to corona. is there anything else that we cna do? maybe make a mikve with a hose or something