I see no real risk to using most of the commercially available "dissolvable" pacing materials after septoplasty. These include Gelfoam, Sinufoam, Merogel and a few others. They are all pretty much gone in a week. I hesitate to use Surgicel, as this takes a bit longer to go away, and I'm a little concerned about it possibly promoting synechia formation.
Generally, I do not use any packing after septoplasty alone, and I use Gelfoam if I've reduced the inferior turbinates at the same time.