I'm guessing it simply may have been that you were doing the process on the wall instead of on a table or floor. If you switch between brands you will notice some brands want you to spray the material, others want you to spray the batting.
Spray basting is a huge time saver on large quilts, it may not be worth your expense on just doing childrens quilts for charity. Instead, you could use that money to make a a few more quilts!