According to Leviticus, regular sex is unclean also.
Not everything in the bible is a "sin". What is a sin? We could define sin as any "transgression of the law". And that's accurate. However, the law is a bit more nuanced than people give it credit for.
Part of this is because some of the law was dedicated to health but these were not doctors. If a person got sick because of a shellfish allergy then they may have thought shellfish were bad to eat. Many people are allergic to shellfish. But many people are allergic to many other things. They were told not to do it in general out of fear for the general safety of the population; not not "don't eat shellfish because eating them is a crime."
And so that's what the Rasta Youth is asking for. "Make it makes sense".
So there are some things that would get you kicked out of Israel (if not executed). If you consumed blood, for example. However, coming into contact with blood, in general, made you "unclean". Students of the bible should try to understand this context of "unclean" as unsanitary (or not "sterile"). (But their standards of "clean" would have still been way below our standards)
They had to pay more attention to prevention because they didn't have cures like modern medicine has today. We also have allergy medications today. So all these things must be read in context. It's not wrong to have allergies. I have seasonal allergies. Is breathing pollen a sin? Of course not. So you can't avoid everything you or other people might be allergic to.
They couldn't see viruses and things on a microscopic scale but they did notice a difference in sick animals so they could tell from the body's reaction that it was sick. This is why, even if a clean animal died of sickness, you were to treat the meat as unclean. Unclean basically just means you could catch something.
If you don't prepare Chicken right, although it's clean, you can get sick. Likewise, if you don't use a condom you can get sick. You CAN... doesn't mean you WILL. They didn't have condoms so their risk of catching an STD wasn't 100% but was much higher. And so without laws telling people that they were "unclean" until night time, this was a good way of keeping diseases from spreading.
This is why it is hilarious to me (at the same time not funny at all though) when people who are against covid-19 protections, like mask wearing, try to use the bible for justification. Doing so shows they have no OT biblical understanding whatsoever. The bible doesn't tell you not to have sex. It simply says that if you have sex you shouldn't be touching everything until a good amount of time has passed. And that's because germs can't live for too long outside the body.
So as much as many people get off by pretending to be better than you for all the laws they think they're keeping, it almost doesn't matter if you don't understand why you're doing. And that's kind of what Rasta Youth was saying and I agree with that. Oral sex is "unclean". And? All it means is that you shouldn't perform oral sex and go around touching other people's food, blowing your breath in their faces, etc.. That's nasty. But unlike the Israelites, I have indoor plumbing and can hop in the shower whenever I need to as well as use antibacterial soap. They didn't have these things so they had to do the best they could. If the bible was written in 2020 it may have said "and thou shalt have a bidet in thine house and at least one air purifier per level".
They often lived in tents with no sewer system. So where is the human feces? Where does the extra water go after a rain? A lot of us who descend from Jamaica also remember taking a bath in a river, waterfall, etc. If you take a bath in an unfiltered water source, then you are exposing yourself to pollution, including human and animal waste, as well as you are contanimating the water with your own waste. How many mosquitos were attracted to them? All these things matter to the overall health of a nation. But if you don't understand at least what they were trying to accomplish with certain laws then you may still be breaking the "heart" of the law. Likewise, if you wash and sanitize yourself that is also a way of keeping the "heart" of the same law you think others are violating by performing and receiving oral sex.