Here's the scoop on coin laundry. As people mentioned there's one on the corner of Grimalde Del Solar / Schell in Miraflores. That's a little east of Benevides and a few blocks north of Larco. As of 2016 it's 10 soles to wash 10 soles to dry for a smaller mid sized top load. I think they have a larger drier for 18 soles. The place was clean but they didn't seem too friendly. I think they also have a dry cleaner or a lot of equipment in back and it smelled strongly of solutions. There's also another coin laundry directly south. If you go south on Schell I think it turns into Berlin. That laundromat is on 336 Berlin, Coin Super. It's 8.5 to wash, 9 to dry. It's a side loader with a larger mid sized load. I think they have a pretty big machine for 18 soles also. I heard the side loaders are better but I didn't like these as much as it didn't seem like they used much water to rinse and my cloths, even with Eco-friendly free and clear detergent, still smelled a bit like detergent afterward. There’s also only four settings, cold delicate, warm perm press, warm normal, hot normal. Which is a drag if you want normal cold. But it might have been like that at the other place too. The Berlin place is a little dirty as far as lint on the floor and stuff but it's not real gross and didn't bother me. A good thing about this one is it's on a corner with doors on both sides and a ton of airflow. A lot of the detergents and bleaches are toxic so this is a good benefit. The one on Berlin was more crowded but I was there on Sunday and still able to get machines. The place on Grimalde has 6 washers, the Berlin place has many machines. With both places you pay them and they give you tokens to put in the machine, so you don't need change. There's also a place further north on Schell right past the expressway, but it's 11 soles for side loader washers, 11 to dry.
If anyone finds a place to buy eco-friendly detergent please let me know. Thanks to everyone who posted.