BongChoka,

I wouldn't take one person's experience with Blu-Tak to be representative of the common experience. It's a silly putty-like substance that shouldn't cause any damage to your M22s. I had my M22s attached with it (one pea-sized blob near each corner) for about 3 years. When I decided to wall-mount my M22s, the Blue-Tak was a bit of a pain to get off completely, but it didn't cause any damage.