Fleas and vinegar

A co-worker told me that he sprayed his cat who had a lot of fleas with a mixture of one part vinegar to 3 parts water. He heard or read this somewhere on uses for vinegar. He said it didn't hurt the cat and killed the fleas. He was tired of the frontline and other chemicals for fleas. Has anyone else done this or heard of it?

I Use vinegar in water to rinse my cats after bathing them to restore skin ph. But there are members here that use vinegar for fleas.