Many folks have informed you as to why NOT apply wet, because the wet application will react with the aluminum reflective particles, also I always follow the manufactures recommendations, they know more about their products than I do.
The Big Squeegee works great to apply large graphics like you have, however I would contact Dale at Big Squeegee
http://www.bigsqueegee.com/ to see if he could make you a custom Big Squeegee 62" wide.
Check out the video of Doug Allan applying a 4x8 print with the Big Squeegee.
[video=youtube;6RtNWHe9ojg]https://www.youtube.com/watch?v=6RtNWHe9ojg[/video]