Did you mean this
post (
http://elementscommunity.org/forum/index.php/topic,15610.msg213730#msg213730) by Malduk (couldn't find one by shantu)? If that's it, then sorry, but you got the challenge completely wrong, since in that thread you are referring to, one was prohibited to use the trainer, while in this one you're
supposed to use it to see how much poison you would get in the AI. If I was allowed to use PvP, as Malduk said he did, of course I could easily get it much higher, since I would have total control of both sides of the field. Also, if the OP said you could poison yourself instead of the AI, it would be much easier as well.
There are a number of additional things to consider when doing it on trainer, since the biggest problem is to work with the AI to have it do what you want. Just to begin with, you can't let it blow up any virus too soon, and you have to control its discards so it has exactly 7 plagues in hand, and not any other unused permanent or spell.