What can I use to give oral sex to someone who has HPV with out passing hpv? And how effective is it?

HPV protection. Latex or polyurethane squares (sometimes called "dental dams") can be held against the vulva during oral sex to reduce the risk of transmission that way (use a glycerin-free flavored lube on both sides of the dam to increase pleasure for both partners). This is not an absolute guarantee against infection, but does help substantially. The long-term plan should by hpv vaccination for men & women.