While some adults do get laryngeal HPV
papillomas, the relationship and risk as it related to
oral sex is vanishingly rare. You estimate of less than 1 in 30,000 is likely in the right ball park and if anything, is lower.
2. Dr. Handsfield has recently addressed this questions very well. I will just paste a slightly modified version of his answer in here. "As far as oral sex, HPV, and oral cancer, just forget it. HPV is infrequently transmitted by oral sex.