Correct way to use line locs

Have a Hurst Line Loc installed and can't seem to get it to hold worth a darn.

Locs installed between the master and front portioning valve,
Bled the brake system,
New shoes (NAPA),
Can hear a light Loc click when switch activated and...
NO LEAKS.

Witch is the correct way...or does it matter?

#1 Apply brakes then activate switch and hold switch on, or
#2 Activate and hold switch on then apply brakes?? I think I head someone state they have a one way valve to the brakes when activated. I didn't try #2, but #1 didn't work for me....I'm just a :tool: