I embed tea light holders in my palm everlasting pillars. I like simple and cheap. I use Play Dough to fill the tea light holder, put a nail I have cut off in the wick hole in the mold, cover with plumbers putty and guerrilla tape. The nail holds the play dough filled tea light holder in place. Works like a charm and the play dough can be reused. Don't know if the same process would work for a votive holder.