My son, the sewing machine repairman, recommends cutting the thread and pulling the remaining thread down through the needle but not because of the tension. If you were to pull thread back through the entire machine it would also bring any dust, dirt or debris on the thread back through your machine as well. Over time, it can add up to quite alot of dust. The small loss of thread is minor compared to servicing your machine more often. Although he is happy to service machines, he also likes to inform machine owners how to keep from visiting him more often. Guess I did something right when I raised him:-)