10% is the highest you can buy without a prescription. Personally I don't think benzoyl peroxide works well at all as a wash. It has to stay on the skin for extended perioRAB of time as with cream or gel based formulas.
I got one from the dermatologist that was called Brevoxylwash or Brevoxywash... one of the two - but you can get it in different strengths.* If you use that in conjunction with a good Tazorac cream and some Doxycylclene antibiotics... you should be good to go.* Just make sure the Tazorac cream is 0.1% to get good results.* Talk with a good dermatologist and you will be acne free in 6 months.
Panoxyl, it comes in two different strenghts, 10% and one other. It says to use for 2 minutes then rinse. You can buy it over the counter. I have purchased it in the bar form but I think there may be a liquid soap also.