Giving guests the trade code is kinda dicy. They might just grab your shiny and leg it.
I'll help you out, my ingame name = vincent. Whats your ingame name (so I know I'm connected to the right person)?
How do you wanna do this? You have 2 shiny porygon right? I currently do not have the evolution items for porygon myself. I assume you want to turn 1 into porygon 2 and 1 into porygon z? Then let's just tradeback both first. Then interupt so you can put dubious disc on one of them and resume?
Also, are you able to trade on home? I got a shiny graveler I wouldn't mind evolving afterward.