I read Mel's book about 2 years ago and I don't remember sprouting in vermiculite... hmm I'll have to dig it up and read that section.

#1 - I do all of my seed sprouting a soil based of either 50% Compost/ 50% aged cow manure, OR 100% unfertilized commercial potting mix. I avoid the "made for seedlings and transplants" mixes because they tend to add nutrients and I have doubts about the quality control of the ferts, adding another variable for failure...

#2 - If you like the soil free option of sprouting in vermiculite, sprout in rockwool instead. You can buy about 48 rockwool cubes for about $10 on amazon. They are marketed for hydroponics use but function in soil for seed starting to transplant purposes just fine. Once they sprout and are ready for transplant, you just pull the cube off the strip and plant the entire cube! Excellent drainage, no vermiculite mess, inexpensive, and the roots hold firm! I'll upload an image I use.

Good luck!