Peggie Hall wrote:
steveJ wrote:

I would dilute the bleach first with water. Mabey 1/2 cup to 5 gallons
of water. This will kill mildew.


Not in that dilution. Nor will bleach in any dilution emulsify oil,
diesel or any petroleum product so that it can be washed away.

Most effective is a 500ppm (free chlorine) solution made with
about 13 ounces of bleach (5.25% sodium hypochlorite) per gallon
of water, with about 6 ounces of vinegar to acidify it.

That said, if there's oil in the bilge, the chlorine solution will
be almost, if not totally, ineffective for sanitization, and as
Peggy points out, will not solubilize, emulsify, or otherwise
remove the oil.

Keith Hughes