The regimen I followed was a daily shower with hibiclens (be sure to use moisturizer, since hibiclens is irritating), and twice a day putting the mupirocen in both nostrils and wiping it on my butt (just put some on toilet paper and wipe) for
two weeks. Take my advice for
what it's worth as I am not a doctor.
Finally, you should probably see a free clinic. Trust me, they've seen worse, and they'll be professional about it.