The most common reason for the lingering smell of stains and chemicals is poor ventilation during the application. That doesn't quite help you if you've already applied the stain, but for future applications make sure to do the work in a well-ventilated room with fans for circulation, or outdoors. This is especially important to stop the smell from spreading to other objects in your home.
You can also try using water-based stains over oil-based as they tend to smell less. If you've already applied the wood stain and still smell the chemicals, try finishing with an encapsulating water-based topcoat. This is completely fine to use over oil-based stains as long as you wait for 48 hrs minimum before applying it.