I would say yes I flushed my of kush for a week and 1 day first day I used florakleen and it really helped a lot when it came to the quality of smoke ...it takes out all the built up salt ..I grew in soil as well and yes they say 1-2 weeks of flushing I'd say it also depends upon how much nutrients u used during your grow ...a week should be more then enough I would think ,the last two day of flush I used ice cubes and and colder water to try and get her to produce more resin as the shock of the cold does this to the plant ..I hope this helps any information besides the growers here would be found at growweedeasy.com best site besides this one lots of information.. cheers