I've been using Proflex for a while now. Great product but as some people have mentioned, it can be a real mess to apply. This may be old news, but here is a tip that was told to me by an RV parts guy. After you apply your bead, dip your finger in a pot of dish soap. Suddenly the proflex stops sticking to your fingers.
Instead of behaving like glue, it suddenly feels like playdough. The first couple times, I pressed down pretty hard and ran my finger along the length of the bead, but that caused two problems: 1) the bead thinned behind my finger and piled up under it to a point where it sluffed off to the sides like a furrow behind a grader AND 2) too much handling can create air pockets in the bead...which you'll have to go back and fix.
So, after running your bead and then dipping your finger in the soap, gently pat the proflex down with your finger moving along, patting it down into place(you may need to refresh your soap finger from time to time). Once the proflex is exactly where you want it to be, GENTLY run your finger along the bead to smooth it, being careful not to drag extra product along with you.
You'll soon find that you want to proflex everything. Heck, I've even done my rivets with a dollop and a pat or two. Makes a pretty good water proof cap.
Anyway, hopefully this helps make applications a little easier. I'd like to mention that practice makes perfect, AND I don't have an data as to how the dish soap will affect the proflex in the long run, so please use this information at your own discretion.