[HPforGrownups] Riddle = Slytherin?

[Kimberly Roth]

No: HPFGUIDX 84579


  Many have suggested that Harry's green eyes could mean that 
  he was related to Slytherin. If only the "Heir of Slytherin" can 
  open/find the chamber, both of which only Harry and Riddle did, 
  could that mean that Harry is also an Heir of Slytherin?>>

Hi.  New to the list... this always confused me, because didn't Ginny open the chamber?
Granted Riddle used her to open the chamber, but where does this "rule" come into place?
Also, since it was already preciously opened by Riddle, couldn't anyone who knows how
to talk "snake" know how to open the chamber?  Just curiuos

Kimberly