Your comment made me perform a series of test of various blowing. The variant using the tongue is not that much more difficult. The key is to make the air escap

Your comment made me perform a series of test of various blowing. The variant using the tongue is not that much more difficult. The key is to make the air escape between your lower lip and the tongue. But whatever you're more used to is the best, as the gesture works best when used spotaneously.