Most of what goes into the grey tank is dishwater with liquid Dawn detergent. When I drain the tank I am getting an enormous amount of suds, so much so that it fills up the dump station line. Has an...
I have two words for you : FABRIC SOFTENER! It'll kill those suds lickety-split...
I learned this trick in a laundromat- A washer started overflowing suds when somebody put too much soap in it and the attendant ran over with a bottle of Downy...one splash and the suds collapsed/disappeared.
You'll have to experiment with amounts, but I guarantee you it will work.