this thing's incredible

The Best Detergent for Workout Clothes Is a Century-Old Soap Bar

When I left for college, there were certain items that my mom decided were absolute essentials. And while I never did use the pop-up hamper, and all the stick-on Command hooks fell down within the first few weeks, the weirdly retro bar of laundry soap called Fels-Naptha did become an important bulwark against the indignities of dorm life. A spilled Solo cup of Merlot? A pant leg covered in bike-chain grease? A spot of olive oil that hadn’t budged in three spin cycles? They all disappeared after a quick scrub in the bathroom sink.

Fels-Naptha is a borderline-miraculous stain pretreatment. Like Coca-Cola, it’s a 19th-century innovation named for an ingredient that turned out to be highly problematic. (In this case, the namesake substance — naphtha — gave you cancer.) Also like Coke, it was reformulated without the bad stuff. It’s just plain old (noncarcinogenic) soap these days. Really strong soap, that is: Besides my mom (and her mom), it’s popular with people who make their own laundry detergent. People who are serious about clean clothes, in other words.

So Fels-Naptha remained a part of my laundry tool kit after graduation, even as recently as this weekend. (Chocolate sauce, white pants; I don’t want to talk about it.) But I only recently figured out my favorite use for it: washing workout gear. I’ve always found myself running out of athletic clothes before it was time to do laundry, and I don’t think it’s just me. (I’ve been told that owning enough sports bras to make it between loads is essentially impossible.) When I started running more seriously a few years ago, this minor annoyance became a bigger problem. The solution? Since Fels-Naptha is just a bar like Irish Spring, I’ve started leaving it in the shower. Once I’m done with my normal post-run rinse-off, I give the clothes a quick scrub with the soap, roll everything around for a few seconds, then hold them up to the shower head to wash the suds out. The whole process takes less than a minute, and the next day, I have dry, sweat-stink-free clothes ready to go. I’ve been able to get rid of all the shorts and tops I sort of hate, and can always run in clean clothes without needing to drop rent-scale money on new gear. Now, I just need to be better about instructing my houseguests on which soap is for people.

Writer Carson Griffith swears by the Lestoil her mother introduced her to: “My only hope to remain somewhat presentable between keg parties and study sessions was my mother’s original go-to. Here’s a pro tip: Lestoil works wonders even when you don’t have time to do laundry. Rubbing some of that caramel-colored oil on a stain can get rid of it without a wash.”

Writer Maxine Builder uses Spray ‘n Wash Pre-Treat Stain Stick to clean her clothes: “Immediately after a stain happens, I rub the product onto the spot and the fabric, and let it sit for as long as possible. Before I go to sleep, I’ll wash the product out in the sink with cold water, wring it out, and let it dry. When I wake up, the stain has lifted and the clothing is ready to wear again, with no one the wiser.”

Writer Sadie Stein washes her expensive delicates with this Japanese washbasin: “I like to put my unmentionables to soak with a little Woolite, or Forever New, or if I’m feeling flush, the Le Labo–perfumed Laundress detergent; soak them overnight; and then give them a good swish and rinse. And its washboard, of course, is for cleaning underpants (or as some men like to call them, ‘panties’). I imagine if you were wanting to wash up any evidence of a murder, it would be very useful, too.”

The Strategist is designed to surface the most useful, expert recommendations for things to buy across the vast e-commerce landscape. Some of our latest conquests include the best women’s jeans, rolling luggage, pillows for side sleepers, ultra-flattering pants, and bath towels. We update links when possible, but note that deals can expire and all prices are subject to change.

Every editorial product is independently selected. If you buy something through our links, New York may earn an affiliate commission.

The Best Detergent for Workout Clothes Is This Soap Bar