I have made hop tea before and i wouldn't boil any longer than 10 minutes because you wont get any bittering from hop tea so you are just trying to get aroma and flavor out of the hops. If i make a "can" kit i always add DME instead of dextrose, but as to the sugar you are referring too I don't think I've ever heard of it, sorry.
A guy at work asks what I am doing over the weekend. "Not much." I say, "Might brew some beer." "Wow!" Says the guy, "You ever get caught?" - sendkyleanemail