Scrape off as much rubber as you can using a knife, but don't gouge your goods. If the rubber's gooey, put your stuff on ice to chill it out until the rubber's hard enough that you can scrape away at it.
Pour some tea tree oil, eucalyptus oil or orange oil onto a cloth. Touch the oil to the stain, getting the remaining rubber lubed up.
Holding your fingers against the back of the cloth, rub the oil in with your fingers to dissolve the rubber's hold on your clothes and reclaim your gear.
Repeat, till there's no traces of the rubber left. After, throw your gear in the laundry to have it good as new. Pre-treat the area with laundry detergent before you wash, though.
Home Dry-Clean Method
Scrape the rubber again, to prep your piece.
Cover the stain with dry-cleaning solvent, squirting the solvent onto your clothes.
Brush the solvent into the stain using a soft-bristled brush. Wipe off the rubber as it flakes off.
Repeat with more solvent, more scrub action, and more brushing till the rubber's all gone.
Pre-treat the area with laundry detergent, then wash your clothes.