I flew my other plane yesterday, O-360 powered. With very similar conditions to my data gathering in my 150, I could rise the indicated CAT by 8 more F degrees by leaning to peak after applying carb heat.
I agree that in the case of carb ice, prevention by pre-emtive action is much more appropriate than cure following accumulation. That said, if cure is what is needed, things are getting worse fast. In that case, I would rather use, I would rather use everything I have to melt the ice in the least time. It was mentioned that more heat would cause a risk of chunks of ice being ingested. I think this is of reduced likelihood, as the heated air is warming the layered ice, rather than the body of the carb, so it will melt it out as it accumulated - in layers. However, comparing the risks of having inadequate power to maintain altitude, vs the remote chance of a chunk of ice going through to an intake valve, I'd rather get the engine power returned, so I'll use all the heat I can produce.