Your doctor can’t write you a prescription for this sweet relief for your clogged nose—and you certainly won’t find it on pharmacy shelves. A new study reveals that the best congestion remedy is tangled in your bed sheets. Scientists have long-found that mild to moderate physical exercise can temporarily relieve nasal congestion. Push-ups, for example, can provide quick relief by opening your nasal passages and reducing inflammation that may be affecting them. But current researchers…