"The Bible does not provide details as to what sexual practices between a husband and a wife should be considered clean or unclean."
The problem is that in the 1972 they said that oral sex was wrong because Paul refers to “the natural use of the female,” which some were abandoning in favor of what is “contrary to nature,” thus satisfying “disgraceful sexual appetites” and “working what is obscene.”
What makes Paul our boss? The one who says what is right or wrong? The Watchtower writers like to use the writings of the apostles because they like to have authority to lean on. That's not how it is supposed to work.
"Paragraph 9: "Being sexually demeaning. Some husbands pressure their wife to engage in sexual acts that are demeaning and that make her feel unclean or unloved.""
That again refers to oral sex as it is demeaning. See they did that without referring to Paul.