would that be ok or even neccesary
Fontline spot on is different from coppers spot on the latter has been discussed elsewhere on this and other forums.
Coppers spot on is made by Pfizer and contains deltamethrin 1% w/v
Frontline spot on for dogs is made by Merial and contains fipronil & methoprene (and warns of overdose if used for cats)
Frontline spot on for cats is also made by Merial and only contains fipronil
Whilst I am not a chemist THESE ARE VERY DIFFERENT PRODUCTS!
Neither product is licensed for pigs in UK.
Coopers could only be used under vetinary direction.
I have no idea what frontline would do to the health of pig (given you would need a massive dose to meet packet weight) or skin or meat eating quality, let alone to the human safety of those eating meat, so would strongly advise you not to use it.