There is no need for you to respect truces with muslim realms. So you could war for 1 county. Then immediately war again once you drop your levies. Sometimes it is needed and sometimes it is not.
Most of the time I just use Holy war. But sometimes a situation will present itself where I rather use de jure claims to avoid wrong cultural/religion/conquered penalties.
For example Sicily was 6 independent Muslim counties. But one of the counties had the Duke title as well. So Holy war him for Duke title. Then declare war on the other 5 at the same time using de jure cb. win wars. Revoke all titles. Land is mine with no penalties.
Most of the time I just use Holy war. But sometimes a situation will present itself where I rather use de jure claims to avoid wrong cultural/religion/conquered penalties.
For example Sicily was 6 independent Muslim counties. But one of the counties had the Duke title as well. So Holy war him for Duke title. Then declare war on the other 5 at the same time using de jure cb. win wars. Revoke all titles. Land is mine with no penalties.