Could you maybe wash it and then create a starter that you'll decant so as to water it down a bit?
Someone on here put the idea out to not wash yeast, but to make a larger starter so that there isn't anything to "contaminate" it, and that it's just so much easier.
Instead of a typical 1 qt starter using 1/4 lb of DME I add a pint of water and 1/8 lb and save that portion.
There's no concern for flavors crossing, less to clean, no chance for stress, and in theory less chance for mutations I'd think.