I don't have a salt water tank, so I can't give an opinion on the curing if ick.
As a businessman what I will say is this. You mentioned your lps
has 40+ years taking care of fish, he also probably has that much time selling as well. He is going to do and say what he needs to to make a sale. Your right, the products you purchased will help solve a problem, but it might not be the long term, this forcing you to possibly purchase more or try another product.
Don't attack the people on this form, all they are doing is helping you.
You paid for the products you put in the tank. The advice from here is free and should be respected and appreciated.