Digital BW, The Print

I've been experimenting this week with various semigloss,
gloss, and luster barrier papers on my 2200 + MIS UT inks.
Gloss differential appears on them all, mild to medium, as
frequently noted here.

Part of the experiment is learning to apply Lyson PrintGuard. 
I'm doing an awful job. I understand several light coats are
necessary, but even after four, spraying up/down/diagonal, the 
surface is splotchy (though gloss differential is nicely reduced.)

Could someone review a successful technique? I put the print at 
the bottom of a cardboard packing box and spray from about
20 inches away, hoping to reduce how much lands on the furniture.
I've tried it in the open air also, with similar results.

Thanks,
David