Many humans hate tidying up. Aaron Krause isn't among them. 

"It's nice to start with a big stack of dirty dishes, and then everything is clean after," he says. "A sense of accomplishment in a short time." 

Not coincidentally, Krause is the founder of Scrub Daddy, which sells smiley-face sponges and cleaning wands that stiffen in cold water and soften under steamier temperatures. He's also a classic case of an accidental entrepreneur whose story may well serve as inspiration for aspiring founders, or at the very least, a reminder to spruce up your office. 

When Krause discovered the sponge that would eventually become Scrub Daddy, the round perma-grin cleansing sponge that's notched $170 million in total sales across 40,000 U.S. markets, he was the CEO of another company he'd founded called Dedication to Detail. He led the Folcroft, Pennsylvania-based manufacturer of paint finishing systems, which included buffing and polishing pads, from 1992 to 2008. It was Krause's dirty work on this company factory's machinery that would eventually give rise to Scrub Daddy. 

As any mechanic knows, fixing heavy-duty machinery can leave an oily film on your hands that can be painful to remove. Industrial soaps, says Krause, felt like "lotions with rocks" and didn't get the job done. A company based in Germany eventually supplied him with a buffing pad that could scrape off grease without grating the skin off his hands. He created a line of sponges in 2006 for people with similar problems, like mechanics and body-shop owners, but the product never took off. 

Two years later, 3M approached Krause about buying Dedication to Detail--hoping to build out its vehicle appearance line of products. They said he could keep the hand sponges. He sold his first company for an undisclosed amount, put the sponges in a box in his factory and labeled them scrap. Three years later, he used a traditional scrubbing sponge to clean his lawn furniture and accidentally stripped the paint off. He remembered the buffing pads gathering dust in his factory and hoped they would be more gentle. 

He discovered the material that removed dirt and oil from his hands also worked on the furniture, and that it was thermosensitive--acting like a hard scrubber in cold water and a soft sponge in warmer temperature. Krause brought it inside and put it to the ultimate test: the evening dishes. 

"It was an epiphany," Krause told Inc. "This has nothing to do with cleaning your hands." 

A rectangular Scrub Daddy prototype didn't feel right in his palm, so he went with a round design, which, it turns out, makes sense. "Why are sponges rectangular?" muses Krause. "Look around the kitchen: Mugs, cups, coffee pots, muffin tins--all round." 

And that perma-grin shape isn't just friendly: Swiping silverware through the mouth cleans both sides at once. The ridges scrape off stuck-on gunk and the eyes serve as finger holes, so you can cram a Daddy into a persnickety cup.

With the design in place, things happened fast: Several live demos at ShopRite, a chain of grocery stores in the northeast, won local press coverage in Pennsylvania and helped land Krause on QVC. Shark Tank came calling in 2012, and Krause persuaded Lori Greiner to ante up $200,000 for 20 percent of his business. 

What's more, the company has become a household name. In January, Scrub Daddy was an answer to a Jeopardy question and at least one superfan has permanently inked the smiley face onto her body. 

Julie Guleff fell in love with Scrub Daddy's friendly sponges when she saw them on Shark Tank, so much so that in 2015 she got it tattooed on the back of her neck. It was the 13th tattoo she added to her collection, which includes tributes to her friends, marriage, and deceased grandson. 

"My personal motto is nothing is really impossible if you work hard enough," said Guleff, 57, who lives in Port Orange, Florida. "[Krause] was mucking around with a sponge, looking to make a good tool, and struck gold--that's cool."