Just be careful with the Dawn! I poured a whole bunch of that stuff down the drain and ended up with FOAM city! The sensors didn't know which end was up for days because of all the foam! And the sewer hose was all foaming for days.
If I run across a restaurant supply house in a town where I am staying I always try to pick up a couple of boxes of no-foam soap the bartenders use in those brush cleaning sinks. You can't use a foaming soap in the brush cleaners or it explodes with foam.
It is a no foam soap AND it contains a disinfectant that works real good in the tanks.