An English custom (and song) discussed quite extensively here in the past. A "soul cake" was a cake prepared on All Souls' night. Luck-visitors would go round the district knocking on doors, singing a little song, and asking for gifts of food or money. The missus/mistress was simply the woman of the house. The custom persists a little, I think, in Cheshire; formerly it was more widespread in the Midlands and up as far as Yorkshire. Around Sheffield, where I live, it is now extinct, though only quite recently.

The rather odd "soalin" or "soulin" spelling appears to be an invention of Peter Paul and Mary, who were so far as I know also responsible for the modern collation of the song with Hey Ho and part of a Carol (both quite unrelated, though structurally not too dissimilar). It is unlikely that traditional participants in the custom saw it as anything more than a bit of "lucky fun" involving food and drink, but there is no harm in re-interpreting such things in modern and/or spiritual terms; so long as we don't fool ourselves, or others, into thinking that that's what they "originally" meant: we just don't know.

I certainly wouldn't trust anything said about this song or others like it at most neo-Pagan websites, which, I fear, tend to be full of fanciful invention mis-represented as "fact". Nevertheless, I do applaud your general sentiments. We could do with a lot more genuine nourishment of the soul the way things are.