Purple pitcher plant extract and hot baths every few hours in the rash part to try to avoid boils.

Edit: I'm not too worried about this one. Running water and indoor bathrooms helped a lot.

Yes.

Rediscovered Native American remedy kills poxvirus https://www.chemistryworld.com/news/rediscovered-native-american-remedy-kills-poxvirus/3003420.article

Historical sources suggest that in the 1800s, when smallpox still posed a serious threat, the Micmac native Americans of Nova Scotia treated the disease using a botanical infusion derived from the insectivorous plant Sarracenia purpurea, a species of pitcher plant. Now, Jeffrey Langland at Arizona State University in Tempe, US, and colleagues have conducted in vitro experiments with the herbal extract and found it inhibits replication of the variola virus, the causative agent behind smallpox.

Also these.

Home Remedies and Herbs for Smallpox https://www.curesdecoded.com/conditions/Smallpox/224

Should a smallpox outbreak occur, there are several smallpox herbal remedies believed to help fight symptoms. These smallpox herbs include:

• Yarrow - Taking yarrow orally, such as in a tea, is said to help treat smallpox.
• Tansy - Tansy can be taken orally or used as a topical wash to heal smallpox.
• Ginger - To help ease irritation and fight the smallpox virus, it can help to add ginger to your bath.
• Goldenseal - Another smallpox home remedy for the bath is goldenseal.
• Lady’s Slipper - The lady’s slipper herb can be taken orally to help fight smallpox.