cotton ball

Checking to see when haidh terminates

Q: I have been having great difficulty figuring out when my period ends. I usually do not see a white discharge after my menses so I often have to keep checking for dryness. I read that the way to check for dryness is to insert a cotton ball or tissue and see if anything is left on it.

My question is (I'm sorry if it is a bit graphic):

1. What does it mean exactly by 'insert'? As in right before the inner lips of the private part or actually 'insert' into it?

2. Do I let it wait there or remove it immediately?

3. How regularly should I do this?

I would appreciate an answer according to the Hanafi fiqh.