The real issue happens when the total is "$6.66" and then you have people saying, "oh... maybe I need to buy something else...."
And they're completely serious
Let me tell you a little story. A few months ago, this little old lady came to my register to buy some things, not many, and not costly, and well you probably know where I'm going with this. It totals up to $6.66, and this lady, she looks up at the screen, then at me. And she just starts quietly laughing. Nothing insane, but she was just genuinely amused at the price. We talked about how most people get so offended, and she just laughs again. I convinced her to take the receipt, instead of just throwing it away, so she could go try and see if she could offend her friends.
It's funny when people can joke about it. I had a few customers who would find humor in it, or just brush it off, and those were always fine. It's just the ones who took it seriously that made it an issue. I once had two women who had this total, and as soon as I said "your total is six sixty-six," they both gave kind of nervous laughs and said "uh oh, I guess we need to buy something else." And then they got quiet. And you could just see their expressions turning more and more concerned. Like they were truly thinking of all the ways for Satan to appear before them, it would be here, at the end of this piece of receipt paper. And then they decided they probably SHOULD buy something else, just in case. And then they debated about whether they should buy a candy bar or something from some other part of the store entirely. I can't remember what they finally decided on buying, but the entire thing took them nearly 10 minutes more
They seemed content that their souls were safe by the end of it, though, and left more or less happy, if still a little nervous, so I guess that's what counts
And they're completely serious