There are several blogs on the subject. If you have a mulberry tree/bush i say go for it!
The cham can eat full grown worms. However worm life at high heat and food is only 4 weeks tops. Good eatin is at weeks 3-4. You can double the good eatin time by only giving them food every 2-3 days and keeping them in the 20c range and heat them up to cham temps once a week.
For sanitation i recomend starsan. Its sold at diy beer making places. You just dunk anything that touches the worms in it and dont rinse it off (this includes your hands). It will keep the virus and mold down (its meant to keep the beer tank sanitary till the beer has enough alcohol to kill anything in the tank itself).