Actually, you can use the burning of your population as an exploit as well. If you don't have any plans for your own crusade to pass through certain border provinces or port provinces in the near future, you can lower your zeal through inquisitions so that when other Catholic factions ask to send a Crusade through your lands you can open the door wide and invite them in without fear of having half your units jump on the bandwagon with them.

Since I hate sending a Crusade through my own lands and having it mess up all of my defensive armies, I usually prefer the low zeal in all provinces except the port provinces where I build my chapter houses.