Water damage iPhone 3GS

The other day I had the bright idea to go to the pool with my iphone in my bathing suits pocket. I wanted to listen to music but I found a way to forget my headphones. Anyways, so yeah I have my iphone in my pocket and once at the pool decided to jump in the water so I would find the water less cold. Thats when I realised what i just did and told myself: "please don't tell me you just did that". So yeah i don't even want to look at the phone thinking after once dropping it from a 2nd floor face on the ground (no damage) and once dropping it in the water with no damage, this time that was it. So I stay a bit at the pool feeling stupid and letting my phone dry to the sun. After 15 minutes, I decided to go back home and search "bring my iphone back from the dead". I find the rice trick do that for 3 days. Then open my phone put alcohol to kill any corrosion and stuff. Plug my iphone and too good to be true It opens no problem, i unplug it no battery problem, i start texting my friends its working and then when i want to go back realise... no more home button. First reaction ill open it again to see If i missed a spot and try turning it off... no more power button. So yeah i have my iphone back perfectly working, no lcd or battery problem and no data loss, but for my power button and home button... Has this happened to any of you? What should i do? I don't want to order a bunch of buttons to realise its not the button or whatever. Is there a way to diagnose where the problem is from? logicboard? button itself? Looking at the logicboard there doesnt seem to be corrosion or anything.