You say tomayto, I say tomahto. Sometimes 'horrific code' is just another way to do it, perhaps not the best way, but it often gets the job done. Don't confuse your style preferences with some Higher Standard. Nobody appreciates being bashed, but most people will pick up on a good example. I would recommend starting weekly code reviews, and gently making suggestions to improve code. Offer up some of your own code for examination and humbly accept even flawed criticism -- this will set the tone for constructive and collective code improvement.

I recently took a C++ course and was surprised to find that I had allowed myself to get into some sloppy programming habits, partly because Perl is so forgiving.

I guess the main ingredients in dealing with others' code are two cups of humility and a dash of a good sense of humor.