I have tried the make your own basting spray. It is easy to make, but a bit harder to work with than the spray you buy, but it is much less expensive. I am fortunate that I have a large floor area that I was able to spread out and do this, especially as the make your own took longer to dry. I always wash my quilts after I finish making them which also made this method okay for me.
Here is a link:
https://www.youtube.com/watch?v=mVRrFGFXXfc