Topical therapy alone is the best way to eliminate Pseudomonas infections.
4oz of a trisEDTA solution (I prefer T8) combined with 12cc of LA Baytril overwhelms the Pseudomonas's resistant mechanisms and kills the bacteria.
Fill the ear canal or lavage the wound BID for 2 weeks the reassess via cytology and organism counts. If ineffective for otitis media, lavage the bullae to remove inspisated pus and retreat for 2 more weeks.
Oral FQs only lead to resistance since the MIC of Pseudomonas is SO high and the oral dosing is ineffective/incapable of achieving high enough tissue levels.