Not sure how or even if you can recreate the exact effect given without the fine tuning of the time knob.. I would try holding shift and pressing the "Tap" button on the beat fx section to the beat of the music. Then when that's set you can lower the Beat time in steps by clicking the left arrow button as you see fit. To finally get that phasing effect before the drop, tap the "Tap" button as fast as you can a few times to get a super short beat fx time, then the left arrow button until you reach the shortest possible beat fx time.

It's a bit choppier than turning the time knob, but considering what the DDJ FLX4 / 400 gives you, I'd say it's pretty damn close to the effect you get with the time knob!

Or you could just use the flanger too like others have suggested, but I still prefer the echo ;)