I think this is OK, but feel I need to double check....
I am making the Huminator
http://beavisaudio.com/projects/Huminator/index.htm
Can I then make a daisy chain from 2.1mm plugs and connect this direct to the Huminator i.e. Cheap adaptor > Huminator > daisy chain > pedals....
You just have to be sure that your wall wart can supply adequate current for everything plugged into it. As far as the filtering provided by the huminator, it should work OK, but keep in mind that the 100 ohm series resistor drops 0.1 volt for every milliamp going through it. If that's a problem, you can drop it to ten ohms, check the power rating required (P = I^2 * R and multiply by two for margin), and up your caps by 10x. Theoretically speaking any way.
Others with more feet in the real world may have more valid perspectives.