Good find, Daryl. I could not find one less than $40, so just used my thumbs to push equal amounts out of each tube. Worked fine - actually more accurate, because if one tube is a little slow secreting, you can even it up.
Looking at the McMaster-Carr site, it appears that there are a variety of different types of adhesive under the name "Hysol." Only a few are urethane.
If you have access to a Fastenal store, they could order it without your having to have it shipped.