Yep. Can't beat the old ACF50 on the boots. It also revives old synthetic rubber and stops it from cracking with age and helps keep the clamps from corroding . I use on my Cooling/Rad pipes as well.I'm surprised Straticus has not chimed in here promoting ACF-50. He puts that stuff on his cornflakes.
I don't always get automatic notification of threads :/
Tip: If where you are working is a little cold then use a Hairdryer to warm the boots as it will make them more flexible