I'm not sure is washing will get the spices out - it depends on the density of the spices relative to the yeast...
What you can do is prepare a starter using fresh wort, and transfer a minimal amount of the slurry into that. Once grown up you'll have plenty of yeast, but only minute amounts of leftover spices.
Black Mamba IPADrinking:
SWIMBO's cider, Hail Brett
porter, African Queen StoutUpcoming: Wines:
Petit Noir, Liebfraumilch, ShirazMy blog
: Recipes, Wild Yeasts, Yeast Farming, Yeast Exchange & More!