Vegas window gaskets leaving black streaks on sides

[Mo_Mike]

Got a 2016 25.2 VEGAS here, and I guess the gaskets around our "frameless" windows are breaking down and laving black streaks down the sides of the RV after rains..

Any good solutions of something that we can put on the gaskets to prevent this? Was thinking 303 or silicon spray, but figured someone else had run into this issue.. (I know I am not THAT unique)

[cavie]

L A AWESOM at the Dollar Store, Dollar tree.