Using a soft wax (for warmer snow temp) works very well to clean the base. It pulls debris and dirt from the base when scraped off warm. Also a good idea to apply a mid temp wax as a ‘travel or storage wax’ to protect the base.
It’s good for cleaning the base, but what about the old wax? Does it have to get removed at all?
It depends if the wax used to clean the base is temperature compatible with the wax required for the conditions. If you are waxing for cold conditions you should use base cleaner, if waxing for warm it’s no problem to leave the wax on as long as its clean.