I've delayed this for quite some time, but I have not sprayed any of my bags yet. I wasn't sure what to go with, but with reading some of the other threads I decided to go with Collonil. For those that use Collonil, any advice such as how often to spray your bags(i.e. twice per year)? After you spray it do you just leave it to dry for a couple hours or so? Do you really notice much of a difference with using the spray? Any tips would be much appreciated. Thanks!