[sgh]

If I am asked to hold joss sticks at a temple that I am visiting, I would refuse. Since my parents and in-laws are all Christians, I wouldn't be pressured to do so when they pass on. I was once asked if I wanted to hold joss sticks at a colleague's mom's wake. I politely declined and merely bowed to the photo of his mom as a mark of respect. I did so because there were young Christian colleagues present whom I didn't wish to stumble. 

Your parents maybe Christians but what about their siblings? Say you attend funeral of your parents siblings who are not Christian you hold joss stick? Some is same surname as you.