I have the same issue and I've never been able to find a long term solution. The SD7s I have (tried several brands of pads including salmon) are also very grabby, almost scary in the snow because of the lack of modulation. sanding and towing in works for a week or two, but they go south again after that. If you tow them in too much, you'll wear the nose off the pads very quickly. I would ignore the noise, and be glad if they are not too grabby. I'll try disks on my next winter bike.