I'm in the process of cleaning up the seat belts in the off season on my 69 runner and the rear seat belts have sat an eternity under the rear seat and are extremely filthy. I tried running them through my dish washer hoping the high temps would get them clean and it really did not do much. Is there any good method to cleaning these?

I've been looking at these that are new to the market. Youtube how they work...

Foonee car interior cleaner.

I have had great luck using Dawn dish soap and very hot water. Get a course scrub brush, scrubby pad and work at it awhile.

I have no idea if this will work for seat belt fabric but I soaked my '84 Sea Ray boat's interior with interior fabric cleaner and then use my pressure washer to blast the dirt out of the fabric webbing. I first tried soaking and then scrubbing and that was somewhat tedious and not really getting the job done. The pressure washing or actually rinsing worked best. I was hesitant at first but what the hey it's a BOAT interior that has the possibility of getting wet sometime in its life.

Before and After with interior/fabric cleaner soak and pressure washer rinse:

Thanks for the tips. I guess I can try the hot water and dish soap first as its way too cold right now in NY to use my pressure washer although it is going to be up around 50 on Thursday.

I appreciate the ideas.

Soaked my seat belts first in Dawn and water, then stuffed them in pillow cases and ran them twice in the washing machine. Hung them up to dry. They were nice and clean for when I dyed them black.

I used Simple Green.

We detail our used cars and filthy seat belts are a recurring problem. The 2 things that work best for us are either SoftScrub with bleach. Or tire bleach.

Let them soak a while then scrub and thoroughly rinse them. But if you have already washed and dried them, the dirt may have become permanent stains.

I've let mine sit in a pail of hot water with either laundry detergent or Mr. Clean. Whatever, you want something that can cut through grease so Dawn dish soap is also a good choice. If they look like they have oil or grease stains, a scrub of the area with paint thinner (not lacquer thinner) beforehand helps break it down. I leave them soak for a while in hot water then scrub them good with a dollar store scrub brush. Once "washed" I give them a good rinse, leaving them sit in cold rinse water for a while and sometimes rinsing twice. I then hang them to dry outdoors on a warm sunny day. I don't use or do anything that might harm the integrity of the belt fabric.

Hot water, soak, then use original Dawn and a stiff bristled scrub brush to scrub the belt, rinse and repeat until the water is clean after rinsing.

I ended up pressure washing them and not only did it make them look like brand new, it made them very pliable again and felt like new too.

Mike

I did the same but soaked in Dawn / Oxy-Clean and ran them in one of them in a Mesh Bag

OxiClean works great

I put mine in the turkey firer pot and boiled them with some dawn then died them

Omg, you killed them! You killed them!! Murderer!!