I don't think they are fooling around with you. It is true that the carrier in normal, Rogaine-style minoxidil solutions can be irritating to the scalp.
However, as Shed mentions, there are other options for addressing this issue. I'm not sure how 'irritated' your scalp is, but for many of us this irritation is treated rather easily by using an anti-irritation shampoo a few times a week. Nizoral is the most common and is supposed to be good in and of itself for those with male pattern baldness, but others use T-Gel and/or T-Sal.
If your scalp is REALLY irritated to the point that it is severly flaking or you are getting a rash, etc, then I would suggest addressing the carrier solution. The chemical PPG in the carrier of Rogaine-style minoxidil solutions is usually the culprit behind the irritation. So, you could do as the Hair Centre suggests and switch to a cream solution. The only problem with creams is that they tend to be messy and leave your hair greasy.
Another option would be to try a minoxidil solution with less PPG. These solutions exist, but the problem is that they are only marketed, to the best of my knowledge, by one source, Doctor Lee in LA. They are more expensive than the generic minoxidil, but if it works for you it might be worth the cost vis a vis having to apply cream to your hair everyday.
Then again, you might like the cream? It might have affinity with your hair type and it might be easy for you to use?
I would read these message boards and get a feel for the products yourself. There is no one true solution to treating a particular person's hairloss, it is a matter of you examining the options and trying some until you find something that you respond to medically and fits into your lifestyle and budget. Good luck!!