I use Guidemaster which can offset the guide star between exposures randomly by a specified number of pixels of the guide camera. It then guides atthe new position of the guide star.
Here is an animated GIF of 200% crops of jpg's straight out of the canera of the exact same area of sensor 3.8MB
http://d1355990.i49.quadrahosting.co...0_04/crop1.gif
You can see the hot pixels do not move.
Dithering also really helps with noise reduction.
Below is a stack of these ten crops, Notice the hot pixels are gone even without correcting for darks. And the same stack with levels adjusted. Note this was done with cruddy 8 bit jpg's.
By moving by many pixels it also smooths out any noise due to the sensor. It is pointless stacking the same noisy pixel on top of itself as you just enhance the noise or the 'hole' produced by over subtraction of noise by temperature mismatched darks.
Bert