Interesting mate, also I have used Nutrafin to cycle a new tank in the past; however I did not like the product because it's not as advertised, what I mean dump it in and wait 24 hours.
Like you, I found while using Nutrafin you do need keep your eye in how it's working and certainly do add other things to the tank to get a quick result, however Nutrafin does work.
For a more trouble free experience with starting a new tank I would suggest trying a product called StartUp from Prodibio ** many Atlantic retailers carry it** it's much more easy to use with literally instant and lasting gratification.
Within minutes you may safely add fish to the tank.
Check it out also
