I believe that the vast majority of people understand this to be government corruption and waste. He is certainly not getting rid of the corruption with his cabinet lineup.
Instead I believe that he will redefine both corruption and what is considered waste. I believe the trumped version is to get rid of all government overreach, meaning anything that gets in the way of profit by big corporations. Waste will instead be considered every type of welfare and security that does not only benefit the country's wealthy, as such all regulation to protect the common worker or consumer, as well as anything given to help them or the poor will be on the chopping block.
I don't however consider redefining the original pledge after the election to be in keeping with the understood intent of the original pledge.
It looks like Donald Trump will go back on his pledge to 'drain the swamp' once he assumes the presidency. Throughout the campaign, Trump declared to voters that he would 'drain the swamp' if elected. However, Trump's appointments seem to be Washington insiders and members of corporate America; not folks you would associate with changing Washington.
Trump never meant what he said. He never had plans to drain the swamp. As soon as the election was over, he began packing in all of his rich and powerful friends that he vowed to expel from Washington. Trump only said what he thought the voters wanted to hear most, and never planned to follow through with half of what he said.
His entire cabinet is filled with cronies. Most of the folks he selected were big donors or are cashing in on political favors. While I know that's a part of pretty much anyone's process regardless of party, no one else campaigned on draining the swamp. The "outsiders" he's bringing in are out of touch billionaires or people with no other qualifications - Ben Carson, Betsy DeVos, Tillerson! Or they're getting a chance to use their connections to make money - Tillerson, Trump. The "insiders" like Sessions and Cheney are long time GOP cronies. Half his cabinet has been in politics for longer than most of us have been alive.
It is not exactly clear what the 'drain the swamp' pledge meant. It is also certain that many will accuse Mr. Trump, regardless of what happens, of backing out of his pledge. The best way to view the pledge is that 'drain the swamp' is that it means will he bring change to the normal order of Washington. There seems to be little doubt that he will be an agent of change. By that definition, yes, it is likely he will 'drain the swamp'.