This is typically the domain of good old fashioned bleach...but its overuse can weaken the fabric an lead to them not lasting as long.
some folks have decent results using the "oxy" type cleaners.
Another alternative is to get some undies in colors...race car red...stylish black...or maybe even some leopard skin...LOL I don't see to many in plain white...at least the stuff plastered in the magazine pages and Victoria's Secret.
I use dishwasher detergent with my laundry detergent. It even keeps my husband and kids socks white. But if you do it every wash it will weaken them. Put in 1/2 cup of dishwasher detergent, your regular detergent and let it sit over night, you will be surprised.
Most powdered dish detergent have a "chemical sanitizer" (bleach like component). In commercial food service dishwashers are required to reach a relatively high temp...or have the chemical component. a few drops of bleach in a gallon of water has long been a method to purify contaminated water.
I only use the dish washing powered everyone in awhile. I have a bucket and put 1/2 C. Of dish washing powered (cheap kind) hot water in the bucket and my dingy whites. Then I let it sit for a day. Then I run it through the wash cycle through my machine and double rinse it. I hang out my clothes in the summer. I never have to use bleach or anything harsh when I do this. If you decide to bleach your clothes after using the dish washing soap, be sure to wash and rinse all the dish washing powder out. If you don't it eats holes in your clothes. I don't use this often. Only when the get really really dingy.
Victoria's Secret Kevin? I guess the winters in CO are pretty long.... lol
Bob, I still have snow in my yard...and I've been laid up with a herniated disc for a few weeks...you find your entertainment were you can.
Feel better my friend.
Get Well KMS!
I got some epidural steroid injections yesterday...pain level are down and mobility is up...I looks life I we be back on my feet soon.