If you read your Merck index a little more thorougly, you'll find that sodium monoxide decomposes into sodium peroxide and sodium at 400°C, therefore your proposed preparation is suspect ;) It also advises to handle with tongs, and keep water from away from it, as the sodium monoxide will catch on fire in the presence of water :( Using a blowtorch to create sodium is a rather hazardous action, please start thinking about what you post more, a little research would have saved some time ;D If you had did some more research you would have found that thermal process for producing sodium involves heating the sodium salt with carbon, reducing the salt to the metal, see Patent FR694587 (http://l2.espacenet.com/dips/viewer?PN=FR694587&CY=gb&LG=en&DB=EPD)
, Patent US2774663 (http://l2.espacenet.com/dips/viewer?PN=US2774663&CY=gb&LG=en&DB=EPD)
, Patent US1837935 (http://l2.espacenet.com/dips/viewer?PN=US1837935&CY=gb&LG=en&DB=EPD)
, Patent GB486930 (http://l2.espacenet.com/dips/viewer?PN=GB486930&CY=gb&LG=en&DB=EPD)
, Patent FR830353 (http://l2.espacenet.com/dips/viewer?PN=FR830353&CY=gb&LG=en&DB=EPD)
, Patent US279047 (http://l2.espacenet.com/dips/viewer?PN=US279047&CY=gb&LG=en&DB=EPD)
, Patent US2810636 (http://l2.espacenet.com/dips/viewer?PN=US2810636&CY=gb&LG=en&DB=EPD)
, Patent US1493126 (http://l2.espacenet.com/dips/viewer?PN=US1493126&CY=gb&LG=en&DB=EPD)
and Patent US2465730 (http://l2.espacenet.com/dips/viewer?PN=US2465730&CY=gb&LG=en&DB=EPD)
for details 8)
I like your search for OTC approaches. Unfortunately, I've already tried this with NaNO3 and Na2CO3 and didn't seem to get anything resembling sodium oxides. I used a steel can with a loose cover, in the hottest charcoal fire I could make. Maybe my methodology was flawed. If you get any encouraging results it'd be great to hear of them, of course.
For potassium and sodium production, also take a look at http://bcis.pacificu.edu/~polverone/muspratt2/c-0724.html (http://bcis.pacificu.edu/~polverone/muspratt2/c-0724.html)
and following pages as well as http://bcis.pacificu.edu/~polverone/muspratt2/c-0894.html (http://bcis.pacificu.edu/~polverone/muspratt2/c-0894.html)
.
It looks like very high temperature is a prerequisite. The metal vapor is condensed in a hydrocarbon solven, and you hope it does't catch fire. And if you make potassium the raw metal contains a good deal of explosive compounds; electrolysis sounds more attractive to me.