This video shows you how to clean urine from a mattress. This combination of ingredients and steps seems to work well for this woman dealing with a recent urine deposit on a mattress. It seem that she is addressing this urine deposit while its still wet and easier to remove. Anytime you have urine in the mattress it's best to take care while it's wet. Once it dries it becomes much more difficult to clean. I own a urine removal service company in Tampa FL and we use a proprietary urine neutralizer that destroys the odor molecules associated with urine deposits.
In the video the first step is to spray the area with vinegar to neutralize the urine odor. Pet urine is slightly alkaline and the vinegar is acidic so the thought process is that vinegar cancels out urine. Vinegar can neutralize the pH of urine deposits but that has little to do with the ammonia odor emitted from the urine crystals. Vinegar is more likely to reduce the bacteria in the urine deposit removing some of the odor produced by the bacteria in the urine.
The second step in the video is to sprinkle baking soda over the vinegar and allow it to sit for about a half an hour then vacuum it away. The baking soda will absorb some of the off gassed ammonia odor but after the baking soda is vacuumed up the ammonia will continue to off gas and start to smell again.
My recommendation is to Sodium Percarbonate and water. It will do a much better job of cleaning urine from a mattress than the solution in the video.