Extracting stuff you don’t want, then trying to get rid of it after the fact is one approach…
IMO you want to do a better job on your primary extraction.
Colder & faster.
See: It washes the cannabis and then it washes the cannabis some more for some well made crude.
See: Washing Machine "Salad Spinner" tek for how you might start down that road.
Then read of QWET…
Edit: #%>*#<€. There seems to be more to this confusion…if you’re trying to remediate BHO using ethanol you’re doing it ALL wrong. It’s much easier to remove the color while still in hydrocarbons. See: CRC