You will be able to find the information you need here- GuineaDad
You can find the recommended detergent on the page linked above. Personally, I like using Arm & Hammer sensitive skin detergent. Typically, anything without dyes or perfumes is alright. Also, make sure you don't use softener (you can use vinegar if needed). In terms of settings, you can set your washer to bedding/heavy-duty and use features such as presoak, extra rinse, and extra spin as needed. You want to make sure that you set the temperature to cold and flip the pocket inside out. Make sure you don't overdry/use dryer sheets! If the liner is still damp when the drying cycle is over, let it air dry.
I hope this helps!
I use Omo Sensitive laundry powder (don't know if you can get this in the US), and vinegar as a softener. As said above, generally anything without perfumes or dyes is fine as guinea pigs are very sensitive to these things
I use an eco-friendly liquid (you won't get Ecoleaf over there) but same sort of thing - mild, no perfumes etc and a splash of white vinegar in the rinse water. I don't use much liquid either as modern machines here are designed to minimise water use which is a big pain in the rear as things don't get rinsed very well! My fleeces tend to rinse out fine - towels sometimes have to have a second rinse if there are suds left in the drum.
I don't use 'bio' products for the piggies - that's anything with enzymes in. People can get sensitivities to these so I'm very careful with my pigs. Even if piggy is fine trotting round when the fleece is dry, once it is peed on it can reactivate any enzymes which can cause problems with little feetsies. So if a product is advertising how well it cleans at low temperatures it is often a 'bio' product - some are marketed in a very eco-friendly way but I'm really not sure they are!