You can use Q tips soaked in hydrogen peroxide to clean the nostrils and use a lot of saline spray. RegardsDr. J
At three weeks you should be well on your way to healing. I often allow patients to use q-tips gently after showering from the 1 -3 weeks mark and light blowing after that. You are best to ask your surgeon
Dried crusting after rhinoplasty
Dried crusting after rhinoplasty is not uncommon. Sometimes just a warm shower can provide the heat and humidity to loosen things up. Nasal saline is also helpful to loosen crusts. In your case, you should ask your surgeon what to do, as only your surgeon knows exactly what was done in your operation and what is safe for you.
Blood in nose 3 weeks post op
I often have my patients use bacitracin or Vaseline to soften the crusting and dry blood after surgery. It is a little unusual to still have dry blood 3 weeks after surgery. please check with your surgeon