GSS interviewers rated the cleanliness of the homes of the people they surveyed. Cleanliness ranged from dirty (1) to very clean (5). Here are the means by religious affiliation (sample size = 1,893):
No religion 3.98
*significantly cleaner than those with no religion
People with a religion are cleaner than those without one. The means for Protestants and Catholics rise to 4.24 and 4.28 if I remove non-whites.
The correlation between church attendance and cleanliness is .15--a small but statistically significant relationship. And anti-religion people can't claim here that religious people are just lying about the behavior in question.
One more indicator that religious people tend to behave better than the irreligious.