Benzyl benzoate is the only product that keeps our sweet-itch gelding's trouble at bay. For the sensitive areas like his sheath and face we mix it with Johnson's Baby Lotion to make it a bit milder. Never had a problem with irritation in those places.
They're not itching but that (and their legs) seems to be the place they're most irritated by flies, as their fly rugs cover the rest of them.
Will continue using sudocreme in those areas then and just use the benzyl benzonate on their legs