Ozone generators, if they are anything more than toys, will do "wonders" to hoses, rubber gaskets and O-rings. They are often ineffective (for their intended purpose) and should never be used on a boat for this purpose where conventional cleaning as mentioned above will suffice.
Don,
Lest we forget what damage an ozone generator can do to the expensive $$$$ foam in your interior cushions. It can damage foam in a short time and make it literally begin to crumble.
As an example our spa/hot tub has an ozone generator and between that and the bromine I don't know which one is doing more damage except that I have a direct comparitor my brother-in-laws tub. The head pillows/cushions on our tub last maybe a year and the cover perhaps a year and a half at best. My brother-in-law has the identical Sundance tub only one year earlier before the ozone generator "ozonator" was added as standard equipment. His head pillows are about five years old and we use the same chemicals of the same brand. His cover is three years old and looks significantly better than ours which is not yet even a year old (instaled last September).
As Don, Rich & Tim said proper cleaning is the right way to attack a diesel odor. Once you have thoroughly cleaned the boat, and no source of odor remains, you can then spray the surface with a product like
PureAyre (LINK). Cleaning this will take time but letting it fester will only make it take longer to get the smell out of everything.
Masking of an an odor is a bandaid unless you remove the source, eg: clean it. If you don't remove the source there is nothing I know of that will get rid of the smell not even ozone. If left too long diesel odor can also permeate the cushions and fabric. This happened to Tim R. as he mentioned. Diesel smell is one of the toughest odors to eliminate. Sorry to hear you're dealing with this..:cry: