Yes. It doesn't involve taking out the bad cop and having the good cop become the bad cop. If it comes to that, the routine has already failed. It also doesn't work if the prisoner is playing good cop/bad cop.
Well, Greece did it in reverse - bad cop to establish they really might default, creditors, so you better deal with them; good cop to then actually make a deal. Tsakalotos is the good cop. This, incidentally, is evidence that this was probably a deliberate attempt to improve Greece's bargaining position, because otherwise Tsakalotos would have been in charge from the start.
Greece are not exactly prisoners in this scenario, either. Greece defaulting genuinely harms the EU too, so they do have some bargaining power, which is what Varoufakis was trying to entrench.
EDIT: And yes, the Tsipras government seems to have become more popular, not less, since the referendum.