I've always put them in my suitcase - I'm one of those really light travellers and we rarely reach our luggage allowance. On our last trip you could still take 2 x 23 kilos each on Virgin in economy but I know they've reduced this to just 1 x 23 kilos. Even so, our heaviest case weighed only 21 kilos. Perhaps you could put other things in your hand luggage (books, shoes for example) to leave the extra weight for your candles if necessary.