Let's do a deep dive on that harmonica line, because it actually hurts to read.
It's so fucking clunky. That's the sort of thing a teenager would write, both in terms of the outdated monkeycheese humour and the painfully awkward way the sentence is constructed. The simile itself is a non-sequitur and not clever in the slightest - I'm assuming the character speaking the line is trying to open a safe or a vault (Pat likes his heists), and there's no logical or humorous connection between trying to open something and trying to give a frog a haircut with a harmonica. It's not witty or clever in any way. It's just lolrandom humour.
Now we do need to take into account that this line is spoken by a character, not the narrator. But it still fails on every level. Nobody talks like that - even if you have a character that is fond of lolrandom humour, no human being talking to another human being constructs a sentence like that. "About as effective as" is so awkward and sophomoric that you wouldn't find it in real dialogue. It has way too many syllables to have any comic timing, for a start. A human might say "So far nothing's working, it's like trying to give a frog a haircut with a harmonica." It's still not funny, but at least it's not trying to awkwardly manoeuvre the non-joke into position like a drunk trucker reversing an 18-wheeler through a subway station. (Note to Pat: the simile I used there works better because both sides of it share a recognisable concept - the trucker proposition is recognisably awkward, then the audience mentally applies that to the other side of the simile, and therefore understand the level of awkwardness that I intended to convey with regards to your sentence structure. Some free writing advice because, fuck me, you need some.)
What the fuck even is this character, anyway? He's a safe-cracker, presumably a professional. He's a career criminal. His use of "everthin" instead of "everything" is intending to convey that this man is gruff, salt-of-the-earth, and recalls stereotypical "criminal" accents like cockney or pirate drawl. He calls the door/safe "her", recalling sailor/pirate cant. "Everthin" recalls a bald, fat man with scars who doesn't suffer fools. Now try to imagine that ridiculous purple monkey ninja pirate dishwasher humour coming out of someone like that. It makes your brain throw a cog it's so incongruous. If the character was a 16-year-old cyberpunk hacker trying to open the door with a laptop, then that line would work. Maybe they talk like that all the time and the other characters just roll their eyes at their immaturity. That could be quite good comic relief, handled properly. But that character would NEVER call the door "she" or say "everthin". This is just broken. Re-draft and try again.
Congratulations Pat, you managed to write a character into the ground in a single line of spoken dialogue. That's so incompetent it's almost impressive. Thing is, though, Pat thinks this is some of his BEST work. That means he thinks his lol frog haircut harmonica line is actually witty. It's not. It's just random words. Something witty would use a simile, analogy or metaphor that relates in some way to ineffectively trying to open a door. How about:
"No use so far. Might as well have brought chocolate lockpicks for all the good this is doin' "
"Nothing, boss. I might as well drop trou and try and fart the fuckin' thing open."
"Nothing's working. Might as well be tryin' to open an airlock with a toothpick."
It took me 30 seconds to come up with THREE better lines than your best work, Pat, and I'm sleep deprived. Bitch no wonder the Kindle ebooks I write as a hobby and barely promote outsell your "novels". You seriously fucking suck at writing. Not in a "bad for a novelist" way, but in a "5/10 for a 10th grade creative writing assignment" way.