You can also wash the clothes you want to make waterproof (not permanent) by washing just those clothes with 2 to 3 times the normal amount of fabric softener you would use in a full load.
You'll have to repeat the process occassionally but it works pretty good.
Retired USAF, IYAAYAS!
2008 V-Star 1100 Custom Bobber project
2011 Crimson XR with Forged Highway Bars / Hard Bags / Passenger Backrest, Ness parts including Smooth Layback Plate Frame/Mount / Rad 3 Mirror / deep cut grips / drivers floorboards /shifter peg / brake peg / passenger pegs. Witchdoctor black rack, Lloydz filter / timing wheel / VFC III, 7Jurock windshield, Drag Specialties seat.