Spaying the Shih Tzu: Engaging in a difficult, intricate task which, while necessary, will probably never actually be used. (Shih Tzus are, after all, usually indoor dogs, unlikely to be outside unsupervised.)
“Gilding the onion.”
Going to great lengths to play a practical joke.
Just blink it away
Just blink it away: use “magic” to solve a problem, as in “he’s got diabetes, but instead of controlling his diet, he’s going to try to blink it away.” (Reference to the old TV show Bewitched - “twitching his nose at it” would work the same way.)
“Throw to shortstop.”
To help the team by doing what’s expected of you under the circumstances.
“When Tim saw that Jenny was really coming onto me, he should’ve left us alone. Why didn’t he throw to the shortstop?”
Setting the rebar.
Setting the rebar - actions taken now that may pay off later.
“Sure, Joe did all those favors for Lauren. He was setting the rebar for when he makes his move!”
Pointing out the North Star.
Trying to create order out of total chaos. “Obama went down to New Orleans and spent his time pointing out the north star.”
Waiting for the deaf one to listen.
Believing in an outcome that will never happen.
Ladling the stew
Ladling the stew: distributing patronage. "Now that he’s won the mayoralty, he’s ladling the stew to all his major donors.
“Rubbing his elbow.”
Doing something completely useless and harmless and unnecessary because you can’t decide what course to take that would be useful or helpful.
“Dancing with your Great-Aunt Lucy”
Dancing with your Great-Aunt Lucy: Doing something personally uncomfortable or unpleasant for the comfort of a friend or family member–“He didn’t want to go to the party, but his sister was going, and he was afraid her ex-boyfriend would make trouble. Sometimes you just have to dance with your Great-Aunt Lucy.”
“Brewing green beer”
“brewing green beer” - making an all-in short term investment.
“Bagging the weeds”
Pretending to do something innocent while doing something guilty.
“I’m just bagging the weeds” could either mean bagging unwanted plants or bagging marijuana.
Doing the sheen shinney.
Loudly proclaiming one’s greatness while the all other onlookers are staring at your train wreck.
Lighting the volcano
Lighting the volcano: performing useless work rather than the stuff one ought to be doing: “I needed Terry to be getting that report ready, but no, he’s off lighting the volcano for pointy-haired manager!”
“Watching The Brady Bunch.”
Goofing off, but not even doing it with any sense of taste.
“I really needed Erica to help me with the February numbers, but she was too busy texting a friend about her hot date last night. She might as well’ve been watching The Brady Bunch.”
Tipping the milkman.
Tipping the milkman - doing something no one does anymore.
“Matt was so polite last night; every time a woman passed by, he doffed his hat to her. He’s been tipping the milkman lately!”
Filling the water pistol.
Filling the water pistol: plotting or preparing to extract thorough but harmless vengeance on a fairly close friend or associate. “Mark had better watch out now that he made sure Victoria got stuck with the Vernon report; she’s filling the water pistol as we speak!”
Along the lines of the OP: “Boating in Budapest.”
Going a long way to do something nobody really wants to do.
“Annette drove from L.A. to Toronto just to get a bikini wax. Talk about boating in Budapest!”
Fiddling with Omar.
“Did you hear about Paul Reubens? He got caught fiddling with Omar in a movie theater; yeah, his days as a child entertainer are over.”
Installing a pod
“I can never remember your name. I guess I have to install a pod in my brain for it.”
Tickling the negativity.