My personal opinion is that you are not going to be able to get the evaporator very effectively unless you go at it directly..
The evaporator is the 2nd thing in the air's path.. starting at the blower... So i think its pretty unlikely you'd be able to fish it effectively at the evaporator...
If you're gonna do it do it right, the glove box should only take like 10 mins to remove...
For the Y33 guys you could also consider taking out your cabin filter if you have one, the evap should be right after that....
Technically, the passenger vent would probably be closer to the evaporator...
http://www.nicoclub.com/FSM/Q45/1998_Q4 ... Q45/ha.pdf
Take a look at page HA-19 and tel me you think you'd be able to effectively fish a hose around to access the evaporator...