Hi timothy. vertin ,

You could try this script in Axiom. It would be an OnBeginValueChange function linked to a ValueBox that is displaying the string value.
 

public void ValueBox1_OnBeginValueChange(object sender, TagSubscriptionArgs subscription, TVQ tvq)
  {
    if (tvq == null)
      return;

    var text = tvq.ValueToString();
    for (int i = 1 ; i < text.Length; i += 2)
      text = SwapChars(text, i - 1, i);
    tvq.Value = text;
  }

  static string SwapChars(String str, int index1, int index2)
  {
    char[] strChar = str.ToCharArray();
    char temp = strChar[index1];
    strChar[index1] = strChar[index2];
    strChar[index2] = temp;
    return new String(strChar);
  }