Start over
I would imagine that you are not going to get the film clean. To me it sounds as if the crud is there to stay.
If foreign matter is on the film while it is wet and stays on it during drying it will most likely be permanently attached and you can either spot the prints or throw it out and learn from the experience.
My home has water lines that deliver a bunch of organic matter that is well designed to ruin film. For me the soution to the problem was to obtain water filters, both hot and cold, just before my temperature control valve with 5 micron filters. These filters are one of the best darkroom expenditures I have made. One filter might solve your problem if installed where the water enters the house and your pipes in the house are not compounding the problem. I would suspect that the pipes in the house may be adding to the problem. Another solution is to filter the water as it comes out of the faucet. Any filtration will help to be a big step forward as long as they are no larger than 20 microns. The more you enlarge you film in print making the smaller must be the particles caught by the filters. Deionized water works well and is the water produced by a dehumidifier. I also understand that water conditioners can also be helpful.
If for some reason you can not filter or condition your water you can buy distilled water from the super market and use it to mix your ingredients and make your solutions. If distilled water rather than tap water is used for making developing solutions you may experience a change in the rate of development. It has also been reported, but not experienced by me personally, that the use of distilled water in developer or presoaking of film causes additional graininess. Washing of film can be accomplished with distilled water by changing the water 5 or more times. Agitiate the film in the distilled water for 30 seconds, dump and refill thru your cycles.
Distilled water or deionized water can be a very good base to use in making up Photo Flo or other surfactant used in your final rinse even if you have used filters because it should help reduce the possibility of watermarks.
I certainly hope that you are not getting enough crud with your water to make necessary special washing of prints.
Negatives need to be dried in a dust free enviroment. If you are using heat or a fan to dry make certain that the airflow is filtered so that in trying to dry your film more quickly that you do not undo all of your good work For myself I am happy to allow the film to dry naturally.
