The best way to naturally remove paint from wood is the 1-3 vinegar and hot water solution. To be far it takes a lot of elbow grease and is time consuming, but effective and a natural non toxic way to clean paint of wood. I used it for this particular room to take off what I could not just scrap off easily. The paint stripped away easily from this particular room before I used the vinegar solution. Showing just the stubborn need help and elbow grease. And no not finished in this particular spot but I am one that works in multiple areas at a time before finishing a section off, just the way my brain works I guess. Also preparing the wood with sand paper to then once again stain and varnish.
Video of door from that room to just show how easy it comes off with vinegar, You can be told but are rarely shown proof I guess so just figured show your work and how easy it was for the stubborn paint to come off after being soaked with vinegar and having let it sit for 15 minutes. This was for every section. 1-3 ratio of vinegar to warm water and let it sit on paint btwn 10-15 minutes before scraping it off. If my tools were sharp I doubt the need even for vinegar but you work with what you got.
After the few hours of paint stripping to restore the 100 year old natural wood I gave myself a wonderful shiatsu massage.
Large iced filled glass of red to end the night, well just because.