The O's beat Championship opposition in the shape of Norwich and Swansea on their way to a fifth-round clash with Arsenal two seasons ago which eventually went to a replay.
And they have the chance to repeat the trick after earning a trip to the KC Stadium in the third round by seeing off non-league Alfreton 4-2 on Sunday afternoon.
"It'll be a tough game. Hull City are going very well under Steve Bruce at the minute," said Slade.
"They'll be organised and obviously it's quality opposition that you're against.
"We know that it will be tough, but we'll go there for free, try to score some goals, enjoy the cup-tie and see if we can get through.
"We've done it before - we did it at Swansea and Norwich, let's see what we can do at Hull City."