In the Cessna 150/52/172 series, carb heat should be left on until after landing. During a go-around if the carb heat has been previously on during final approach (which it normally will be) the throttle should be opened to full power first, followed by carb heat to off. Makes sense, as the full throttle with carb heat on ensures that hot air dissipates any previous ice build up thus ensuring full power. Carb Ice can build up amazingly quickly with low power and carb heat cold under certain atmospheric conditions.
Read the Cessna 172 manfacturer's POH which states quite clearly: "Baulked Landing - Throttle wide open - Carburetor Heat - cold. Similarly: "After Landing - Wing flaps up - Carburetor Heat - Cold.
For a touch and go you should apply full throttle first - followed by carb heat to cold - same as for go-around procedure.
The aircraft and engine manufacturer would not recommend these procedures unless they had been thoroughly researched and in any case these procedures form part of the certification program.
My advice? You can't go wrong if you stick to the manufacturer's advice. If you think the manufacturer is wrong, then conduct your own measured trials and give the manufacturer the benefit of your expert advice. I am sure it would be greatly appreciated.