i dunno what it is about interp but misinformation abound lest that magical word ever appear in a thread
hit registration in an online setting is a shitstorm that mainly revolves around your fluctuating ping and packet loss in addition to whether or not the server involved is a piece of shit
this is why LAN is amazing and people with consistent 2-20ms ping times are the privileged aristocrats of lag compensated gaming compared to us low-class 50-100ms peasants
interpolation is such a small piece of the hit registration puzzle that it blows my mind people have categorized different interp settings. the video in the OP shows that interpolation (no matter its length) is always calculated into hit registration the same way by the server, meaning you can leave it constant and experience absolutely no difference in hit registration. the lurch or freezing of the player model when the exploit occurs is due to the significant change (400+ ms of aim time) in client rendering time and actual client time
therefore, locking interp settings while you're in a server is a good solution to this exploit that will not change anything for your hit registration
optimal interp settings FOR EVERY CLASS in online play (assuming your connection isn't shit) are
cl_interp 0
cl_interp_ratio 1
if your connection experiences regular packet loss (or if you're a pussy)
cl_interp 0
cl_interp_ratio 2
go read about it for yourself at https://developer.valvesoftware.com/wiki/Source_Multiplayer_Networking