The affirmative defense of unclean hands

What happens if you apply hand sanitizer to hands that are dirty or greasy? You get sanitized dirt or grease stuck to your hands? Is that pretty much just as safe and clean as sanitized hands without dirt or grease?

[Sorry fellow lawyers, I couldn’t resist the thread title. ;)]

Dirt and grease is not always alcohol permeable. Hence, the grease and dirt can still trap and protect bacteria, fungi and viral particles. Hence, the sanitizer doesn’t REALLY do anything.
One should have (reasonably) clean hands, THEN use the sanitizer.
Frankly, I prefer WASHING my hands to using the sanitizer, ALWAYS.
While I was deployed to the Persian Gulf region, I was on a number of military installations. Hand washing was MANDATORY at many of the installation chow lines and some used hand sanitizer as an alternative. In nearly 5 years, I was only sick twice, one when I first arrived, an upper respiratory bug that EVERYONE got from the “critters” in the dust from the sandstorms. The only other time was after sitting in a server room for 4 hours reloading some servers, with a HVAC A/C blowing 15 MPH winds onto me, with whatever dust it still aspirated.
Nothing else, that ENTIRE time. Compared to others, who used the hand sanitizers.
Whilst this is anecdotal evidence, I’ll respect the result.
Who ELSE can tell you that they didn’t even get the sniffles over the course of nearly 5 years?

Plenty of people say such things, each with their own anecdotal explanations…