We installed an ozone generator (Bilgebuster) because my wife is VERY sensitive to the smell of diesel.
Have been most happy with the results. Even clothes left below no longer pick up the scent.
After doing our homework, ozone is heavier than air, so installed it at the upper end of engine compartment. Over time it works over entire bilge. Concentration about same as mountain top according to mfg. New model has plug in ozone generator module to make any future repairs fast easy and cheap.