Hi, everybody! I've a question about towel grips. I'm a heavy sweater, and so, I'm forced to use the towel grip. For the past 2 months, I've been using a towel grip without changing it, and it seemed that I've lost a lot of power because of slip. Now, after I changed the grip last Saturday, I suddenly got my power back. My smashes, clears are great. I think that's because it doesn't slip. My question is, how long can a towel grip last? I play at least once a week for about 2.5 hours. Sometimes, I'll play more than once a week, but that's rare. Based on your experience, how long should I change the grip once? Thanx a lot!!!