I use “Forever New” detergent for my bras, but I do hand wash those. I’m not sure whether a gentle detergent like that makes much of a difference if you’re still running them through a machine? Maybe if you use a garment bag?? Anyways, I think my handwashing method is super easy (because I hate handwashing anything like clothes or dishes) so I just squeeze a little of the detergent into a large stainless steel bowl I have, add cold water, add bra and let it soak for awhile... usually a few hours or a couple of loads of my other laundry stuff... and then I come back and use a gentle toothbrush to rub out the areas where my deodorant likes to rub off onto my bras (it comes right out with barely any brushing after it has soaked for a bit) and then I just rinse out the bra (I find this detergent rinses clean easily) and hang it up over my laundry room sink to drip dry. All in all, it takes less than a minute... maybe a minute and a half at most. Anyways, I do like that detergent. The specialty store where I have to get my bras recommended it.

I put them in bra washing bags, so they're not twisting all over the washer.

Another vote for LeBlanc. I use an unscented version.

I might order some LeBlanc next time I place an Amazon order. Thanks for the recs!

I soak wash like skmom. Only I use either Ariel or Dawn & an ice cream bucket. Let soak a few hours or overnight. Rinse very well. Then either drip dry if the washer is in use or spin dry. Old school top load Speed Queen so it's easy to set the dial to spin.

I use forever new after trying LeBlanc and not caring for it. Forever new has worked well and kept some of my more expensive bras in great shape. I wash undergarments in regular detergent and hot water.