Just a thought, don't know if it would work for ya but, Clorox has a product called Green Works, I use it in the shower sump and gray water tank.
Get a small Hudson sprayer and spray between the liner and hull, soak it good and let run, do it as much as you like, then rinse with water, it will all run to the bilge and will pump OB. Green Works is environmentaly safe so no harn, no foul
Kills the bad smell, leaves a good one
1955 Blanchard 51 Custom ( I got a woody )
On the 8th day God created sailors and evil stood at attention