When slotted into a power (at least a Controller power, like Darkest Night [for DWD] or Mace/Poisonous Ray [for Achilles]) these procs show their debuff effects against the USER when the toggle on/off button is turned 'on' for that power.
I do not know if they affect other ATs, but they double dip in a power like Radiation Infection which can accept both procs. In Controller/Radiation Aura/Radiation Infection's instance, it appears that the entire power+proc's effects are working against the USER. Quite an eye-opener when you are building for s/l soft-cap!
Thanks again for all your hard work, making a quality product for us to use and abuse.