"We've played reasonably proactively throughout," McCullum said.
"We go into every game trying to win. Certainly, for us, it's not about trying to hang on for a draw.
"We see this as a great opportunity to clinch a series win against England and that's something that we'd all hold very fondly. Everyone's entitled to their own opinion, but I certainly don't agree with it."
McCullum took a flick at England's bowling coach David Saker's criticism of the test pitches.
"It seems to be bowling coaches who have an issue with them. It's always going to be the way.
"It's not three or four-day test match wickets, they're five-day grinding wickets, which you have to work incredibly hard on for your fruits.
"I don't see anything wrong with them. They've been pretty good and they've certainly allowed both teams to have periods of dominance."
McCullum went a step further. England want more pace and bounce for their seamers, so as if to impishly goad those with suspicious minds, he reckoned his ideal pitch at Eden Park would be "similar to the last two".
New Zealand are due to announce their third test squad this morning. Seamer Doug Bracewell is a chance to be added to what should be a straightforward group.
Having recovered from the cut foot which sidelined him from the first two tests, he is due to play for Central Districts in their Ford Trophy game against Canterbury in Christchurch tomorrow.
"The three [seam] bowlers have done a really good job at different stages. We'll see how Doug comes through this game, then see which strategy gives us the great opportunity in Auckland."
McCullum insisted his decision to bowl first at the Basin was correct, indeed rating the ploy a good strategy in New Zealand conditions, where the pitches rarely break up.
"Our execution was off," he said of the first day. "We didn't put enough pressure on England long enough and when up against a fine batting line-up you've got be able to exert pressure for a long time."
This is the third decider on the English tour. The tourists won the final game in both the T20 and ODI series, which left McCullum bitterly disappointed at his team's failure to stand up both times. England deserved those victories.
The key for both teams is how far they'll want to pursue victory, even if it means flirting with defeat.
"[Over] five days, you don't really need to chase the game," Cook said.
"That is the worst thing you can do going into a game. If you're chasing the game from the first morning then you can come unstuck.
"You need to earn the right to get yourself into a position to win the game."
