Yeah, oral dosing is the way to go with codeine. As szuko000 said, way too much filler. Also, the dose to actually get a high from codeine even for somone with no opioid tolerance is about 90 mg. or even higher, ime.
Pill insufflation isn't good for you no matter what, but some pills are alot more worth it due to smaller amounts of binders/ fillers and a higher dose of the active.(hydromorphone comes to mind) Vicodin is another one that's kind of a waste to because of all the apap in it. I would defintely stick to oral dosing with codeine.