The 2-0 win moved AFC Bournemouth nine points clear of the Premier League bottom three, the win built on the foundation of a defensive shutout.
"A clean sheet's been a long time coming," Cook told afcb.co.uk
after the game. "It's been since Swansea away on New Year's Eve, which is far too long; we've conceded a lot of goals.
"As a back four we've been working really hard in the last couple of weeks and ever since Manchester United we've looked very solid.
"I'm delighted, it's like scoring goals when you're a defender so a clean sheet is huge for us."
Cook spoke about the turnaround in defensive fortunes, with Swansea's danger men kept quiet at Vitality Stadium.
"We've been persistent," said Cook. "Obviously it's disappointing to concede goals; we're an attacking team so sometimes you are left a little bit exposed.
"Over the last three games we've looked more solid as a team and we're working very hard out on the pitch and on the training ground."
Moments before Benik Afobe put the game to bed with the game's second goal, Cook had heroically made a double challenge in the Cherries' box to keep the Swans out.
The centre-back was modest about his contribution: "That's my job so I was fortunate enough to get in the way. I've been a bit ill this week and I was struggling this morning, so I'm just delighted to get through.
"Now we've got a bit of a break so hopefully I can get on the mend, train hard but also get some rest."