I don't have Asthma, and neither do any of my colleagues, and it makes us all cough. Even when we are doing commercial carpets and staff are in, they start coughing. I use the recommended dilution rate, depending on the traffic on the carpets, and no matter what the recommended dilution rate we do, we still cough.
Once that's calmed down, we always get told how nice the smell is, even the day after!