And would it be worth it?

I've got a heap of Spanish troops massing on one of my borders and I just know they are getting that funny look in their eye... For once I'm trying to play my faction (English) as good catholics so a pre-emptive strike against my brothers is not an option.

Ive got a pretty big fleet, terminating in some muslim provinced in north africa.

What I was thinking is, if I declare a crusade against, say, Egypt, but break the sea lanes first, I could walk the crusade all over Spain and hopefully suck their troops up. I wouldn't put many of my own troops in the crusade at that time because they seem to evaporate when you do. Then after a few turns I could link the ships back up, drop the crusade on Egypt, hopefully full of Spanish troops, and ship an army of ordinary English troops out and into Egypt at the same time to make sure the crusade province is captured.

Has anyone tried something like this? Does it work? Does the crusade count as having captured the province if in fact regular non crusading troops do most of the fighting?