[TimT]

Best way would be to shot blast slab, which would remove the adhesive and the laitance (top layer of concrete). This requires specialized equipment which is not easily available for a homeowner to rent..

Hiring a contractor who has the equipment will be quite expensive, as shot blasters make there money on square foot/day... you probably have a tiny slab..it will cost a fortune to have a blaster come to your house

I'd buy the smallest size of any of the chemicals/products mentioned, and test and see which one works best... The go with that..