Not sure the Paki's have the political wherewithall to do that and there are some sticking points

-the Pashtuns do not much care for the Pak gov,
-the tribes on the other side of the border (in Pak) are Pashtun relatives
-the Karzai gov probably does not have the political backing to support Pak troops on Afghan soil (any more than the Pak gov does to support US in Pak)

However, the idea has a great deal of merit and if it is not being pursued now it should be.

The Paki's have spend a great deal of blood since 9/11 trying to pacify this area, more than America has in Afghanistan by some numbers.

Given their nuclear status, Paki cooperation on dismantling Al-Queda, and the nature of the Paki-Afghani relationship, I would hope that this type of approach has been explored in depth and the current ops are a reflection of the failure of all other options.