You can use Oxyclean (r) in a high-efficiency washer. You just use a whole lot less, just as you use a lot less detergent. With a HE washer, you need to get an idea of how much water a given load size is going to use and adjust your cleaning chemicals accordingly. One note: your HE washer won't use as much water to rinse. If you put too much chemicals in, some (or a lot) will remain in the fabric. This often causes allergic dermatitis: unexplained itching, tiny blisters, welts or hives. Most HE washers lets you adjust the rinse so more water is used when you need it. I do this for large loads of towels, or when stuff is really dirty. Start out with less chemicals than you think will work and adjust up in quantity if needed.