Yes, you would do that if you can't Soft Reset (That helps you hit your delay more accurately, but it's still very possible without SRing). And remember to try and hit A right as the timer hits 0, you need to be accurate. But you already have experience with RNG so I'm sure you'll be fine :)
If you have any other questions, ask. Btw you'll probably be off by a couple seconds on the first try, you just have to adjust your timer by changing your target second. So if you were aiming for 14 and got 16, you would make your target second 12 instead.