I have used spray glue on poly many times. Poly is all I have and they recently have gotten in the spray glue in a local shop near here! Boy am I happy. I am skimpy with it and try to make one can last for at least 2 if not 3 quilts. I also use pins.
I am not sure what the difference is between 505 and any other kind of spray. Is 505 a brand?
I haven't tried the Elmer's glue method yet...need to do it when I can leave it on the table overnight to dry. With the spray it goes together quickly.