Sorry for the long question but here it goes:

I know it takes a week to grow out of you scalp but how long will it keep growing into your hair? Some people say 3 days( until its out if your blood) and some say 30 days( when there is still small traces in you body) ?

If I always have short hair (1/2 inch or less) and get weekly hair cuts , can't I just cut my hair after two weeks of smoking and have all new clean hair growth?