All the common dry snake beddings are fine...the only time you cannot use PAM is with moist beddings. So fresh out of the bag cypress or other wood beddings would need to dry out first (water makes the active ingredient in PAM breakdown)

As for Bed-a-Beast I think it too starts out moist and then drys out...you would want to wait till it dries out to use PAM on it (not to mention the PAM has to dry anyway before you replace your snake)