This is an interesting thread. I don’t know if what I experience is the same thing, but after challenging workouts I get a chemical smell. It’s usually right after I’m done and lasts for 10-15 minutes. I thought (think?) it’s my body/sweat reacting with my kit, but maybe not. I don’t think it’s ammonia. I don’t know what acetone smells like. I am generally well-fueled, definitely don’t skimp on my carbs, and try to hydrate well. The smell isn’t always there after a tough workout, but it shows up from time to time.
I’m relatively new to cycling, but not new to challenging workouts. I am new to lycra though, so I thought it might be that 
At least I’m glad I’m not alone.