What is the meaning of this sentence? I know every word in the sentence but can't figure out the meaning of it.
Flander: Homer, I'm in a rhubarb of a pickle of a jam here. I was all set to go off on vacation when I get called up for jury duty. Oh, it's a corker of a case. Seems a man drove up onto a traffic island and hit a decorative rowboat full of geraniums. Now they're trying it as a maritime offense. So, anyhoo, how'd you like to use my beach house, free of charge?
Homer: I only get two weeks of vacation a year and you want me to spend it in your lousy beach house?
Flander: Well, if it'll seal the deal I'll take a look at your septic tank, see if I can get her humming again.
Source: The Simpsons S07E25