Oh, I can? Cool advice! How do I get the people with bad hygiene that we're talking about to follow it?

(You have lost the plot; your response amounts to explaining how soap and water works to someone who has just described their office mate's tendency not to shower.)

Get a new job? You can't be that "in charge of" a repo if you can't enforce rules this basic. In fact, I don't understand how you can enforce something as (being polite) unusual as banning .gitignore and yet can't enforce build system hygiene.