from what the dermatologists have told me, the strongest over the counter stuff you can get is creams that contain Benzoic acid. It is the active ingredient in one of the expensive acne treatments with lots of ads on TV in Australia - but here you can get it a lot cheaper from the chemist in a cream called benzyl; not sure about in Canada.
I have found with greasy skin, I was my face with a face cleanser and I use a toner and an oil free moisturiser.
I also make sure my moisturiser has sunscreen in it because sun damage causes lots of wrinkles. Over here the dermatologists say the best way to prevent wrinkles is to protect your skin from the sun and don't smoke.
I don't use any of the expensive stuff, I don't think they work any better and are just marketing.