The Os earned a money-spinning fifth-round trip to the Emirates Stadium after Jonathan Tehoue's late equaliser secured a 1-1 draw against the mighty Gunners.
Arsenal will again be big favourites to go through to a quarter-final at Manchester United.
But, incredibly, Slade feels his side can improve on their memorable Brisbane Road display.
"We didn't think we played that well in the first half on Sunday," he said.
"Arsenal have had a look at us, but we will still go there and give a good account of ourselves, although it gets even more remote in terms of getting through."
Source: PA
Source: PA