the DOD Gonkulator is -as far as I know- a combination of a distortion and a ringmod pedal. For the ringmod part I can show you an example. It's not exactly the same you'll need, because it is based on the ringmod of the Yamaha CS-80.
test-ringmod.axp (5.1 KB)
The left part of the patch is a very basic synth for testing purposes only. It consists of a midi-input, a single saw-oscillator, a filter and a vca controlled via an ADSR-Envelope. On the far right side is the main volume and the audio output.
The interesting part is everything in the middle that has a label on it.
The ringmod AD envelope allows you to create a speeding up and/or down sound of the ringmod. The depth control regulates the amount of the envelope affecting the oscillator. You can omit these as the Gonkulator pedal has none of these.
The modulator is a simple sine oscillator with a speed control. You can use this control to tune it to whatever note you want...even to B flat, as in the pedal.
The math/* object does the actual ringmodulation.
In the mix object you can dial in how much of the not affected signal and how much of the modulated signal you want to hear.
I hope this is helpful to you.
PS: Buy your core! Fiddling and tinkering around with it will solve many questions.