They were very popular in the 70's, and in malls in the 80's there were many kiosks in the middle where people would demonstrate the carving of candles.
I have my vats, and carve candles, however, the fancy unity - candles, like the ones she shows do not sell very well at all. The ones that do are the novelty candles.
Here are the type that literally fly off my shelves. If I want any customers to buy these I have to set them up after my shows start otherwise the other vendors snatch them up before anyone else gets a chance to see them. LOL
I also make a "Christmas Tree" carved candle (beware, the pics are not so good) and people like those as well, but they are fragile, and the "branches" easily break off so I do no shipping of these type at all.