Mrsfarmer- I'm sorry to hear of the hard time your husband is going through, I can relate to it. Whiler I've never had that particular obsession, I know what it is to have irrational thoughts (and you know they're irrational) but can't stop them from intruding. Having had OCD (mostly obsessional problems, I don't really have compulsions much) I can understand the horror of the disease. I've done much better on medications, especially the SSRI class of antidepressants. Does you husband take an SSRI?
Anyway, I hope he gets well soon,