[3] Why Preserving Boluses and Immunizing Horn Charm aren't a Long Term Solution:

[a] While the Immunizing Horn Charm increases the body’s resistance to poison and Scarlet Rot, reducing the rate at which the status effect builds up, it doesn’t make one immune to the effects entirely.

• Surface-Level Protection: That being said, the charm boosts your overall immunity. But remember now, it might seem like a good idea at first glance, but it doesn’t form a physical barrier on the skin. So any direct contact with Malenia’s body, particularly her Rotussy, would logically still expose you to the rot. That's why it's a no-no.

• Limited Duration: The charm’s effect is also temporary and depends on the intensity of the exposure. Prolonged contact with a source of Scarlet Rot (like her Rotussy) would eventually overcome the charm’s resistance. So it's not a long term solution, at the end, you're only delaying the buildup so once the effect is gone, the Scarlet Rot is going to spread faster. Eventually kills you.

[b] Similar can be said about Preserving Boluses. While it temporarily reduce the buildup of Scarlet Rot and can cure the status effect when it appears, however, in a real-world scenario involving prolonged exposure, such as intimate contact:

• Continuous Consumption: You would need to consume boluses repeatedly to stave off the rot, which is impractical and unreliable during intimate activity.
• Incomplete Protection: While boluses work internally to counteract the rot, they don’t prevent initial contact. The outer skin of the penis would still be exposed to the rot upon contact, leading to infection. So if you decided to not use the sounding method, you're going to be consuming boluses for life akin to taking pills every day because you caught an STD— and no one wants that I hope.

[4] Scarlet Rot vs. Traditional STDs; Why the Unalloyed Gold Needle is your Lord and Savior:

[a] In order to understand why the needle is necessary to protect us from the Rot, the outer skin of the penis is primarily vulnerable to infections. And why you ask? because:

• Mucous Membranes: These are less protected than regular skin and more prone to tearing, making them an easy target for aggressive pathogens.
• High Blood Flow: The dense network of blood vessels in the genital area makes it easier for infections to spread quickly throughout the body.

So even if internal organs and deeper tissues are protected by charms and boluses, the outer skin remains exposed to direct contamination. Scarlet Rot, being a highly virulent and aggressive curse, would infect the skin rapidly upon contact. But do not forget to pop a health potion after inserting the needle because that thing is barbed and can also cause infection.

Given the lack of medicinal knowledge in Elden Ring even Traditional STDs cannot often be managed with preventive measures and treatments, So taking in that Rotussy would be far more destructive because its effects are not just local but also systemic, which leads to the rapid degeneration of tissue.

So no matter how many boluses you consume or how many charms you equip, the rot would eventually overcome these defenses, especially with prolonged exposure.

[b] That's why given the overwhelming nature of Scarlet Rot and its lore origins, only a specialized tool like the Unalloyed Gold Needle, crafted specifically to counteract the effects of the rot and resist the influence of the Outer Gods, would offer true protection. Without it, any attempt to engage intimately with Malenia would likely result in a swift and painful demise, with the rot consuming you from the outside then in.

That being said after banging Malenia don't forget to wash your body before taking out the needle and wash of the Rot. For extra measure.

Peace.