Many famous hoodoo spells utilize the heart of a swallow as a magical ingredient -- typically to use in love spells but occasionally for gambling and other works. The swallow's heart is a very old item of magical power; the oldest reference to it I have seen was in the 17th century by Wecker.
Unfortunately for hoodoo's modern practitioners, even if they're willing to kill a swallow and remove its organs for magical use, it's not actually legal to do so in most places. Therefore replacements must be found. In the past I've offered for sale my own replacement for the swallow's heart in the form of a red wax bead filled with appropriate powders and minerals (but this was a limited time deal -- you'll currently have to make a special request if you want one.) Another simpler replacement I often recommend these days, for charm bags, is a piece of rose quartz, easily found available in most spiritual shops -- including the rose quartz products at Lucky Temple's store.