...Hate to toss 2 kegs down the drain.
Don't toss it down the drain!
I haven't had very many spoiled batches ...maybe two or three over the last 25 years...but I have never had to toss any. Unless there are really nasty things going on, a soured or out-of-balance beer can very often make a good marinade for roasted, barbecued, and grilled meats. Try that before you toss anything...why waste it if you don't need to?