I believe Pygmy recommends using a soldering iron or soldering gun to heat the hot glue bond to the point that it can be weakened and separated when the time comes to remove the forms from your hull. Once the form is pulled from the boat, you'll file, scrape or sand the glue remnants out of the hull. That's why using white glue may not be in your best interests -- it may create a more permanent bond between the forms and the hull than is desirable. Best stick to the Pygmy instructions. The hot glue is easy to work with a soldering gun. Read forward in your instructions to the point where you're advised to remove the forms. Chances are that Pygmy has given you some advice on removing the forms.

Jim