go with the aircraft/engine ops manual.
Rotax manual in my aircraft, Use carby heat when required to keep airbox temp at 21Deg C. so, in winter, its not uncommon to fly the entire flight with carby heat on... and the reason rotaxe's should always have an airbox, so heated air is added before the filter.
only ever had carby ice once in a rotax, on a long descent from 8500 to sea level mid winter. and of course, i forgot to keep carby heat on in cruise.
And what exactly are you trying to do when "Clearing the carby" clearing it of what exactly?