Swimming with a piercing

I got my helix pierced three weeks ago and I want to go swimming tomorrow (in a pool). It looks healed on the outside but I've read that inside it could not be healed yet. I was told not to use any sterilising solutions on it except for water and salt, but nothing with alcohol. I'm worried that bad bacteria can get in there when swimming, do you guys think it's okay to sterilise it just once after swimming or should I listen to the piercer?