What I use on sets I have rescued is some peroxide 20-30% paste typically found for hair bleaching, along with typical low % peroxide liquid found pretty much anywhere to thin it out make it a good consistency, plus laundry booster with TAED. Be careful when using this kind of mix, as too long and it will start removing the color out of the plastic itself. If you are doing 2tone sets, I highly recommend doing each base key color in a separate batch as it makes it easier to pull them out and stop process. Darker key colors seem to get done faster.