I'm a former body piercer (from, like, 25 years ago, but still). My suggestion would be waiting until you are no longer getting any discharge from the piercing site. After one month you should still be cleaning off dried lymph and serum from around your piercings. Until there has been nothing to clean off for at least a week straight, I would not recommend changing jewelry. While the fistula-the 'tube' of skin going through your earlobe--is forming, it's very delicate, and will be easily damaged by changing jewelry.
How long that takes is going to depend on your body; some people will heal very quickly, other very slowly. I don't recall that my ear lobes took more than a few months to fully heal. I have two piercings that I've had for decades now that still aren't fully healed, and probably never will.
As far as cleaning goes, saline or plain water and mild hand soap are your best bets. Alcohol, iodine, Hibiclens, hydrogen peroxide, etc. are all disinfectants, and will harm the piercing as it's trying to heal. (Hydrogen peroxide is no longer recommended for cleaning wounds, period.)