Just bought orchid seedlings, how to prune and disinfect

Just bought orchid seedlings, the method of pruning and disinfection:

① first washed away the dust on the orchid seedlings and the soil and sand on the roots with water.

② then cut off the rotten roots, broken roots, withered leaves, diseased leaves, residual flowers and dried false bulbs of dried orchid seedlings. Don't hurt new buds, flower buds and good roots.

Finally, ③ smeared the incisions of the roots or leaves of the orchid seedlings with sulfur powder or charcoal powder or soaked them in 1000 times potassium permanganate solution, rinsed for 15 minutes to dry, and put them into the basin when there was no moisture.

All tools and tools used in ④ should be sterilized in advance.