I have done 冷凍 for a few times. It takes about a week for the 'jiu' to peel off and there will be a light shade left behind. I did it at 皮膚科醫生在診所做 and cost about $1000 each time.
The doctor said it's mainly caused from beauty centre where they use towel but do not sterlise thoroughly after use and the wart will transmit from one person to another. That's why I don't do anymore facial outside now.
After doing 冷凍, have to be careful not to expose under the sun as this will make the shade darker so I usually do it in autumn or winter time. Also, there is no guarantee that the wart will be totally killed and it will come again when you are weak, tired or stress.
However, it might disappear one day for no reason, might be your body can fight it after some time.
I still got tiny bits on my face but the doctor said as long as they do not grow bigger or darker, no need to do 冷凍 as it is difficult to control the area for 冷凍
and the time for the shade to disappear is difficult to estimate and varies from time to time and takes longer when you are getting older becoz of the slower metabolism rate.
Hope this helps.