Sometimes masking a horrible smell with pleasanter ones only seems to makes things even more gag-inducing. Maybe try aromatics like eucalyptus and curry plant etc rather than cloying sweet smells?
"What is hateful to you, do not do to your neighbour".
Shame the pigs are being kept in sheds. Presumably if they were outdoors, the smell wouldn’t be so concentrated and would dissipate more quickly? We only buy free range British pork, so hopefully not contributing to your problem, while supporting uk farmers.
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