You can vacuum bleed them, assuming you have a vacuum bleeder setup. When I put buckhorns on my sporty I bled them the normal way. (pump,squeeze, turn bleed screw) It did not take very long the normal way.
A whole thread for ya HERE
I'm gonna make one of them 'shooters' out of a push cycle water bottle, spare
bleed nipples, tubing, a valve out of a fish tank's air hose and the connection
off a tyre foot pump.
Connect the thing up to a spare tyre for the air pressure to pump in one end,
use the fish tank valve to control fluid flow out the other and into the
Post a pic when I've made it.