To wash the greenhouse from the inside, do not use ordinary water. Most often, a solution of baking soda is used, where 30 g of soda is taken on a ten-liter bucket of water.
It is also effective to use solutions of mustard, vinegar, soap, potassium permanganate, and other disinfectants.
When washing, please pay attention to the cobwebs and the probability of stumbling on a hornet's nest. The applied solution should then be washed off with plain water.
Not only greenhouses walls should be washed, but also metal pipes, electrical wiring, and heating structures.