First, I want to caution you about taking the advise of the grow store people. Many of them do not even grow----and they are salespeople first. Their job is to sell you as much as they can. I am often amazed at the myriad of things they recommend that are actually not needed. And those nutes are about 3 times as expensive as others that will probably work just as well.
However, as I am not familiar with them, can you tell me more about them. Organic or synthetic? How many parts? What is the N-P-K of the parts? How much do you feed and how often?
I do not flush my plants and do not believe that they taste of nutes. And I habve never heard of a nute line that recommends flushing every week--that just seems crazy and wasteful to me. Unless there is a huge salt build-up from the nutes, I cannot imagine a reason in the world to flush every week and I cannot imagine it being good for the plants.
I have started using AN products as GH has sold out to Scott's (and I refuse to support Monsanto). For hydro, I am using Jungle Juice 3 part. For organic soil grows, I am using Earth Juice.