The xylene concoction works well on the thicker head rubbers but the airbox ones in my experience, and a couple others too, are just a waste of time. The soften up but warp and shrink weird and get rock hard really fast
I bet that sealer will just about fall off after soaking the boots
Thanks for the advice. The airbox rubbers were already a little deformed and softness was uneven. Plus I had them soaking already by the time I read your comment.
So, I have them drying on old light bulbs.
The one on the left is fresh out of the soak, the others have been drying for a few days. Those have nice uniform softness and have a nice Velocity Stack shape. I'm very pleased with the results.
Those other boots with the sealer on them are soaking now.