Before performing a surgery a dental surgeon treats his hands according to Spasokukotsky-Kochergin method. What antiseptic is basic in this kind of treatment and how is it applied?

Answer options

1. 0,5% liquid ammonia solution in two washbasins, 3-5 minutes in each
2. Tissue with 98%ethanol, 5 minutes
3. Two tissues with 5% liquid ammonia solution, 5 minutes each
4. Two tissues with 96% ethanol, 5 minutes each
5. Tissue with 0,5% chlorhexidine digluconate, 5 minutes