A little follow up from yesterdays post.
The basting spray that I purchased was from the June Tailor company, so I can only comment on that particular product as it's what I used.
This product is odorless and colourless, I did however have the front door open just in case but there was no smell, the only problem I found was that I forgot to shut the door and the dog got out...... The spray is removed by washing once the quilt is finished and is recommended for use with 100% cotton fabrics and batting. It's also recommended that you spray directly onto the batting, not the quilt backing or quilt top. I didn't have any problems with it gumming up my machine needle and it was extremely easy to quilt. It's extremely easy to re-position any of the fabric if you get a little wrinkle and it holds for up to two months. I used a queen size sheet on the floor to grab any over spray.
It's available in many stores, my first choice was just to go to Hancock's and grab a can, then I found it on special at Joann's. Once I'd purchased it I found it at Walmart for a fraction of the price. So it's worth shopping around for the best price, why pay $13 a can when you can get it for $7.00.
If you are interested in reading about the various brands available you can find a wealth of information here, just type in spray baste into the search. This is the site that I used to decide which brand to use after reading all the comments.