Possible Clues:

• Sty wallower
• Mother of piglets
• Pigsty dweller
• Foment
• Spread for growth
• Seed
• She might get seedy, perhaps, in 17 across
• Sailor turning on wife who drops litter?
• One might perhaps to be seedy in the sty
• Sounds like 21 across in a swinish sort of way