If you're looking for a herbal treatment for blisters, you can use diluted tea tree oil or diluted oregano oil on the blisters to help them heal. Tea tree oil toothpaste is also great for oral HPV.
My favorite herbal remedy for HPV is lemonbalm tea. Lemonbalm (also called Melissa) tea is fantastic for stress. It's a natural sedative that reduces anxiety and depression and promotes good sleep. I drink a cup every night before bed.