can using compressed air damage my ipod while it is still on?

I got sand in my ipod when I was at the beach, I would try blowing it out which people told me to not do that since it will make it worse. I don't think it was too much sand either. I would also plug my earbuds and charger in and feel some sand in those areas. The internet said to used compressed air. I didn't want to do the cotton swab and paper clip method because I didnt want to risk more damage and i have had my ipod for a few weeks now and it is brand new. I took the tip of a thin, clean paint brush and brush around in the audio jack and charging port. Geek Squad told me nothing can fix sand in my ipod. Total jerks too. I bought compressed air and used it while my ipod is still on and used it again a few hours later just in case there was still sand in there but I did turn off the ipod and did little spurts of air. But the first time i used the can, the ipod was still on and I didnt do little spurts of air, I would hold it in place for a little bit. Could my ipod gotten damaged while it was still on?? I had my ipod for a few weeks now:( and hate for it to damage now. I also got it from walmart with no warranty.