IPHONE WIPE COMPLETELY UNTRACEABLE EXT?

Ok so i have and iphone and my brother is very smart on computers and phones anyways he said he can see my deleted messages if he hooked my phone to his alienware(hi tech laptop) and i don't sext or nothing but i want my own privacy i have nothing to hide but is it possible to make my phone 100% unseeable and or no traceable like wipe it 100% but the problem is. Wanna keep my games and my contacts please help

An alienware isn't necessarily "hi tech" it's just a computer with good parts in it, what makes the difference is the software he's running. He needs a forensic program to be able to see deleted data. The fact of the matter is if he has forensic software and can properly use it you can't fully erase everything off of it. In order to avoid forensic software from recovering deleted data you need to run a DoD spec 8 pass erase. This process will delete EVERYTHING and you will need to reinstall the phones operating system (long story short if he's good you can't hide it!). Here it is, unless he has a specialized Operating System such as Kali Linux or Backtrack5 he can't really do much, he would need high end software to do this sort of thing (if he has Windows he doesn't have what he needs because most of this software is not widely available for Windows, and the VERY few versions available for Windows is going to cost him several hundred dollars).