American girls and british accents?

my son who is at uni (he is 19), wants to travel to america in his gap year, now i think this is wonderful and will broaden his horizons, but he thinks that because ( in his own words ), he has a cute british accent he is going to be successful with the local girls ( i told him that nice manners and a good personality will be more of a help), ive told him he has been watching to many films where the american girls fall for the cute british guy, usually played by hugh grant, but he is adamant, could all you lovely american ladies please confirm that his accent wont get him anywhere, so i can show him this